Choice Remains Between Outlook Mobile and Exchange ActiveSync Clients

One of the most common questions I am asked concerns mobile email clients. Should Microsoft 365 tenants deploy and use Outlook Mobile or select a client based on the Exchange ActiveSync (EAS) API created by companies like Apple and Samsung instead? I’ve written about this topic before but it’s worth summarizing the current state of the art, so here goes.

OWA for Devices

Ten years ago, Microsoft jettisoned its focus on OWA as the premium client for mobile email connectivity. Trumpeted with some vigor at the 2014 Microsoft Exchange Conference in Austin, OWA for Devices, as the client was known, leveraged the engineering investment to create a high-quality browser-based client. Essentially, OWA for Devices was a wrapper around the full client to allow it to run using the native browser found in all mobile devices.

The OWA for Devices plan allowed Microsoft to bring a wide range of features to mobile devices that couldn’t be built on top of the EAS protocol. It’s worth remembering that Microsoft created EAS to compete with IMAP4 and POP3, so the feature set enabled through the EAS API is limited to basic email and calendaring.

The Acompli Effect

Technical difficulties, poor performance, and the feeling that Microsoft was trying to squeeze a heavyweight client designed for PC browsers into a mobile pot were the fault lines in the OWA for Devices strategy. If you can’t build technology, plan B is often to buy technology, and that led to the Acompli acquisition in late 2014.

Acompli’s signature feature was the focused inbox, or the ability to filter the most important messages into a separate Inbox (actually just a filtered view of Inbox contents). No mobile API supported the processing required to understand what messages were most important to a mailbox’s owner and filter those messages as new mail arrived in the mailbox. Acompli built the necessary infrastructure to copy mailbox contents from Exchange to build an online cache located in Amazon Web Services (AWS) to enable advanced email processing. The Acompli client connected to the processed cache and presented the filtered Inbox view to the user.

Acompli became Outlook Mobile for iOS and Android. The focused inbox became a feature loved or hated by hundreds of millions of users, and Microsoft replaced AWS with equivalent storage and processing based on Azure. Outlook Mobile still fetches cached mailbox content from Azure (now with a customizable synchronization period).

The new Outlook for Windows client exploits the same mechanism to deliver advanced functionality to users who connect to email servers via POP3 and IMAP4. These now-antique connection protocols don’t support many features used by modern email clients, so if the interim processing wasn’t done, the new Outlook for Windows would be restricted to a basic feature set. This simple but salient fact is ignored by those who protest when they discover that Microsoft synchronizes mailbox content to Azure for processing.

Outlook Mobile Continues to Lead

Coming back to the original question, I continue to recommend that organizations focus their mobile email client strategy on Outlook Mobile whenever possible. It’s a solid client for both iOS and Android that easily outpaces EAS-based clients in areas like email features and information protection. The client feature set continues to evolve, with the latest initiative being a new contact editor (MC746321, last updated 5 July 2024, Microsoft 365 roadmap item 384869). Apart from more reliable synchronization of contacts with Exchange Online, the new contact editor (Figure 1) supports enforcement of Intune policies such as preventing copy and pasting data in the editor. Outlook Mobile is better integrated into Intune device management too. In summary, from a corporate IT perspective, Outlook Mobile ticks many boxes. Its advantage over EAS clients in this area is unlikely to diminish.

But life isn’t always simple and corporate IT doesn’t always get to implement their choice. The era of BYOD means that an incredible number of devices connect to Microsoft 365, and it can be hard to move people from a native email client. Old habits die hard. However, I see an increased uptake in Outlook Mobile usage, possibly because features like sensitivity labels have rolled out in more tenants. My view is anecdotal and based on a limited set of data, but it seems like that’s the way things are going ten years after Microsoft choose Acompli as their new mobile email client.

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Customizable Outlook Mobile Synchronization Between 1 and 90 Days

A change so good that Microsoft announced it twice in MC696167 (7 December 2023, last updated 24 May 2024) and MC798682 (last updated 14 June 2024) tells us that Outlook Mobile users can customize the synchronization window for their device. Both are associated with Microsoft 365 roadmap item189809. According to MC798682, the rollout started in early June and was expected to finish by late June 2024. I didn’t see the update until July 2.

The synchronization window defines the period for downloading email and attachments to a device and enables offline access to mailbox contents. MC798682 says that the period extends between one and 30 days, but as you can see in Figure 1, the iOS client offers the ability to synchronize data for up to 90 days. Microsoft says that they will expand the size of the synchronization window from 90 days after they confirm that everything works well in production.

The now-renamed Outlook classic client has had a customizable synchronization period since the introduction of “drizzle mode synchronization” in Outlook 2013, but this is the first time that the iOS and Android clients get similar control.

Synchronization Basics

Synchronization happens between Outlook mobile and the cached copies of user mailboxes stored in Azure. Being able to set a minimum one-day window might seem strange, but it addresses the need some organizations have to restrict the amount of corporate data stored on a device. If messages outside the window are needed, Outlook mobile can fetch them from the server if a network link exists. It just takes a little longer than if the messages are cached locally.

Previously, Outlook mobile synchronized 500 items per folder by default with the ability to download up to 1,000 items per folder if necessary. Outlook periodically trims the data cached on the device to keep the items under the configured limit. With the introduction of the new synchronization window., Microsoft is limiting download to a maximum of 2,000 messages. Restricting the number of messages downloaded to the local cache makes sure that the Outlook mobile client can function without problems, especially on low-end devices. Microsoft says that they’ll increase the maximum for synchronized items and the size of the synchronization window in future versions of Outlook mobile.

Configuring the Synchronization Window

To configure the synchronization window, select the Settings option in the client. In the General section, select accounts and then the account for which you want to configure the synchronization window. Go to the Data storage setting and configure Sync settings with the number of days for the synchronization window (Figure 1).

You can also toggle the Include attachments option on or off to control if Outlook mobile should automatically download message attachments received during the synchronization window (Figure 2).

Through Intune controls, administrators can set a default synchronization window for devices and stop users changing that window. The keys for the two settings are:

• com.microsoft.outlook.Settings.DaysToSync.
• com.microsoft.outlook.Settings.DaysToSync.UserChangeAllowed.

The maximum value settable through Intune for the synchronization window is 90 days, which is the same as seen in the client.

Outlook Monarch Gets Synchronization Too

The first support for offline access in the new Outlook for Windows (aka Monarch) was also due to begin its rollout in late June 2024 (MC798674, Microsoft 365 roadmap item 178030) covering mail, calendar, and contacts. Only a limited set of actions are covered, including the important ability to read and send email. So far, I haven’t seen the update or heard of others receiving it, but worldwide deployment isn’t scheduled to finish before late July 2024.

This is an important step forward for the Monarch client, which is already generally available to consumer users (and not without some controversy due to the way that Monarch synchronizes mailbox data from Azure). Microsoft knows that Monarch isn’t ready for prime-time exposure to corporate users yet because features like offline working haven’t been available until now. There’s still a bunch of work to do here before Microsoft can retire Outlook classic in 2029.

Everyone Wins with a Customizable Outlook Mobile Synchronization Window

Synchronization is not rocket science at this point. Adding a customizable synchronization window to Outlook mobile makes sense. It allows Microsoft to address some customer concerns about having too much corporate data on a phone while those who would like to carry around their entire mailbox might be able to do so in future. Everyone wins.

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Outlook and Teams Meetings Both Benefit from Added Protection

Published in message center update MC513052 (last updated 27 April 2023, Microsoft 365 roadmap item 98924) and finally rolling out over May, Outlook (Mac, Windows, and OWA) can assign sensitivity labels for meetings. That is, if you have Office 365 E5 licenses.

Last October, I speculated that Microsoft’s claim of protection and recaps for Outlook and Teams meetings would be deliver very different functionality. Now we see that protecting meetings is a multi-part story composed of:

• Defining and publishing sensitivity labels configured with the meeting protection setting.
• Defining and publishing sensitivity labels configured with Teams online meeting settings. Meeting organizers require Teams Premium licenses to use sensitivity labels with Teams online meeting settings.
• Defining and publishing Teams meeting templates describing different forms of meetings (internal, external, highly secure) to help users choose the right configuration for their meetings. Microsoft describes a concept of three tiers of protection for Teams meetings.

This article covers the basics of creating and using sensitivity labels with Outlook meetings.

Using Outlook to Assign Sensitivity Labels for Meetings

Sensitivity labels have always been able to protect “normal” email, including attachments. Meeting requests and responses are a different form of emails because they include metadata about a meeting (date and time, location, and attendees) that a recipient can use to create an event in their calendar. Given that people often include a great deal of confidential information in meeting requests, I don’t know why Microsoft did not extend protection to calendar messages until now.

When you apply a sensitivity label with encryption to a meeting, the body (text containing details of the event) and any attachments inherit the rights management protection defined in the label. Other information like the meeting title and participant list is not encrypted. This is like normal messages where encryption protects only the content and attachments of messages.

Figure 1 shows how to assign a sensitivity label to a meeting with OWA. Only the set of sensitivity labels configured to protect meetings appear in the drop-down list for users to select from. You can configure a default sensitivity label to apply to all meetings through the sensitivity label policy that publishes labels to users.

A protected meeting operates like any other protected email. Outlook wraps the contents of the message and its attachments in a protected rpmsg message. If the receiving client is “enlightened” (it knows how to process protected messages), it can decrypt the message and display it inline. If not, the user receives a link to access the content through the Office 365 Message Encryption (OME) portal. Note that clients can only open protected messages if the recipient has the right to view the content. The rights are set in sensitivity label properties and will stop people who don’t have the right to view content opening the messages. For instance, the “Internal meeting” label might restrict access to users within the tenant. If someone outside the tenant is a meeting participant, they cannot open the message.

Points to Ponder

While working with protected meetings, I noticed a couple of points worth highlighting:

• You can insert a Loop component in a meeting request created in OWA. Recipients can edit the content of the Loop component even if the sensitivity label blocks edit access. This is because Loop doesn’t support sensitivity labels yet. Current builds of Outlook desktop (subscription) doesn’t support adding Loop components to meeting requests.
• If you assign a restrictive sensitivity label to a meeting, you might stop meeting participants being able to edit attachments. This might be what you want to do, but it’s a change in behavior that users need to understand.
• Sensitivity labels determine rights based on email addresses. If someone forwards a protected meeting invitation to someone else, they might not be able to access the content if the rights specified in the label doesn’t have an entry that matches their email address (or domain). One advantage gained is that if people forward meeting invitations without permission outside the organization, the external recipients won’t have access to the meeting content.

Sensitivity Labels for Meetings in Outlook Mobile

Outlook Mobile can open protected messages (decryption occurs on the server) and can process inbound events to include them in the calendar. However, the meeting body is not decrypted (Figure 2), which means that the user knows they have a meeting to attend but can’t see the text explaining what the meeting is about unless they open the meeting with Outlook desktop or OWA. However, the deeplink for the Teams meeting remains usable because it is not encrypted.

In addition, Outlook mobile cannot send protected meetings because the client doesn’t include the encryption technology needed to apply protection.

Don’t Rush to Deploy Sensitivity Labels for Meetings

Introducing protected meetings isn’t something to do on a whim. Like any information protection project, some consideration is needed, especially if sensitivity labels are already deployed. That topic deserves a separate article, which I’ll get to in due course.

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Moving from Administrator-Performed Delegation

In February 2020, Microsoft added delegate support for mailboxes to Outlook mobile. At the time, an administrator had to grant full access permission for a mailbox to a delegate before the delegate could add the mailbox to Outlook mobile. Message center notification MC250343 (April 12) covers the provision of end user options in the mobile clients to delegate permissions. The update is described in roadmap items 67273 (Android) and 67274 (iOS) and has now rolled out to clients. I used Outlook for iOS version 4.2118.0 for this review.

End User Delegation

The roadmap item says that a user can give someone else (the delegate) permissions to manage email and calendar events on their behalf. In normal Outlook-based delegation, this would happen by granting the delegate read access to the mailbox and read-write access to the Inbox. However, as noted below, Outlook mobile has its own approach to delegation management.

To see the new option, go to the settings section for the client and select your mailbox. The Share Your Inbox option is towards the bottom of the screen (Figure 1). As you can see, I already have a delegate set up for my mailbox.

Click Add People and input the email address of the new delegate. You can select only people from your organization. Next, decide what permission the delegate should have (Figure 2). Because this is an end-user delegation rather than one assigned by an administrator, the approach and nomenclature used aligns with Outlook desktop where the assignee grants a role to the delegate.

• Review: Can only read items.
• Author: Can read and create items.
• Editor: Can read, create, and modify items.

You can change the role assigned to a delegate at any time by selecting the delegate under Share Your Inbox and selecting the new role.

Note the caveat at the bottom of Figure 2. Access is only granted to the Inbox folder meaning that the delegate can process inbox items but can’t, for instance, go to the calendar to create a new meeting.

If the delegate needs to send email on behalf of the user, an administrator must assign send as or send on behalf of permission to the delegate.

Granting access is silent. The permissions are present, but the mailbox owner must inform the delegate that they can now add the mailbox in Outlook mobile to access the Inbox. In addition, administrators don’t know anything about the delegation, which is perfectly fine until they’re asked to solve problems. Or, as in the case of tenant-to-tenant migrations, an audit of mailbox permissions is needed to make sure that the permissions are taken over to the target tenant.

The Problem

All the above sounds good and I am sure that Outlook mobile users will be happy to delegate access to their mailbox direct from the client without administrator intervention. The problem is that Outlook mobile has done its own thing to make this feature work, likely by exploiting the Microsoft sync technology which connects Outlook mobile clients to mailbox contents. The delegation applied to the mailbox doesn’t work with Outlook desktop or OWA. For example, if you grant editor access to your mailbox to a user and they try to add a shared folder in OWA to open the mailbox, they can’t see any folders. In Figure 3 we see OWA after a user assigned editor access to my mailbox has added it as a shared folder. OWA displays my name and the option to create a new folder. There’s no trace of the Inbox, and attempting to create a new folder generates an error.

Slow and Odd Approach

Given the number of support incidents which often pile up relating to delegate access to mailboxes, it’s probably wise for Microsoft to take a phased approach to enabling end-user delegation in mobile clients (even delegation which only works for mobile clients). First the Inbox, then perhaps the calendar, and finally full access, or something like that.

The target audience for this feature are users who don’t use Outlook desktop or OWA (where delegate access functionality is more developed). Although it’s good to see end-user delegation appearing in Outlook mobile, creating delegation which doesn’t work for other clients is bad practice. In this light, administrators might prefer to control the process and continue to have users request delegate access to be configured for their mailbox, including access to the calendar and the ability to send delegated email. If that’s the case, the method outlined in this post remains the right way to configure delegate access for Outlook mobile.

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Outlook, iCloud, and Contacts

I last wrote about managing contacts in Outlook mobile in March 2017. Lots has happened since, especially to expand the functionality of Outlook mobile. But one thing that hasn’t changed is the frustration of multiple contacts in Outlook for iOS. I can’t say if the same thing happens in Outlook for Android because I have never used that client (in anger).

In any case, to set the context for iOS, we know that synchronization of Outlook contacts is one-way from Exchange Online to the device. Outlook for iOS needs a synchronization target to get contacts to the native contacts app. Often iOS contacts are stored in iCloud. In this case, Outlook synchronizes contacts to the contacts app and the contacts app then synchronizes to iCloud.

One advantage of storing contacts in iCloud is that this handles contact synchronization with multiple Apple devices (for example, an iPhone and an iPad). However, in this scenario, Microsoft recommends that contacts for an account are only saved on one device as otherwise the potential for contact duplication becomes very high.

Originally you could only add, update, or remove contacts through Outlook desktop or OWA, but in 2017 Microsoft added the ability to add, edit, and delete contacts through mobile clients. Contacts added through the iOS contacts app aren’t known to Outlook and therefore don’t synchronize back to the contacts folder in the user’s mailbox.

Outlook Contact Synchronization

Updates made in Outlook contacts (in desktop, OWA, or mobile) are synchronized by Outlook mobile to the iOS contacts app. Outlook must be running in the foreground (or active in memory) for synchronization to occur. Outlook contacts are clearly marked when viewed through the iOS contacts app because Outlook creates an application-specific link for the contact (Figure 1). When clicked, the link opens Outlook and displays the contact details.

The contact synchronization mechanism is different in Outlook for Android and isn’t handled here. However, the basics are similar. Outlook synchronizes with the native contact app and handles contact updates processed on the device.

Synchronization Woes

Synchronization glitches can happen from time to time. Microsoft is working with Apple to resolve why errors occur, especially in synchronization of Outlook contacts from iCloud to multiple devices. Making sure that Outlook mobile only saves contacts for an account on a single device is an easy step to limit the potential for duplication.

The symptoms of synchronization glitches might not be immediately obvious. In fact, they’re more likely to accrue over time. One day you might realize that something’s up when you look at your iOS contacts and find that duplicate contacts exist or that a bug caused bad contacts to be created. For instance, Figure 2 shows that a set of contacts are listed as “Microsoft.” This came about when I updated a bunch of contacts in Outlook to set their company to be Microsoft.

The Solution

One solution is to wait 24 hours for Outlook’s internal contact reconciliation process to run. The reconciliation process is designed to iron out synchronization problems. Most people aren’t aware that the process runs in the background to do things like quashing duplications, so you can leave Outlook alone to solve any problems it finds.

Those who want more immediate action can run one of the many duplicate contact detection and merge apps available in the iOS app store. However, Outlook is the master source for its contacts, so fixing issues on the device isn’t a good solution. Sometimes you need to go all in and have Outlook resynchronize all its contacts to the device. Here’s how to force a complete resynchronization:

Disable Save Contacts

In Outlook for iOS, open Settings and select your Exchange Online mailbox. Turn the Save Contacts slider (Figure 3) to Off. You’ll be asked what to do with the Outlook contacts saved on your iPhone. Select Delete from my iPhone. The last time I cleaned up, Outlook removed 1,522 contacts (most of these are synchronized from LinkedIn).

Check Contacts

Open the iOS Contacts app and check that the problems previously observed are resolved. If not, you can force a complete resynchronization with Outlook with these steps:

• Go to the Help and Feedback section of Outlook settings.
• In the Troubleshooting section, select Delete All Saved Contacts.

Outlook reports that it will retain the contacts and only remove them from the contacts app (and subsequently from iCloud) and the device (Figure 4).

Then go back to Settings, select your Exchange Online account, and reenable Save Contacts for the mailbox to restart the synchronization. You’ll be asked if you want to save your Outlook contacts to your device. Once you confirm, Outlook mobile will download the contacts from your Exchange Online mailbox to the device. You might see a prompt to plug in to a power source while this happens. I never had a problem running this process several times at different states of device power, but I guess it might be a factor if you wanted to resynchronize thousands of Outlook contacts over a slow connection.

Validate Your Contacts and Good to Go

The last step is to check contacts through the iOS app. At this point, you should see contacts that you have added on the device (or indeed, those added by Siri) and the set synchronized by Outlook. The process described above is a sort of fundamental reset to resolve all the synchronization errors since the last full download. Although I can’t guarantee it will work for you, and it won’t do anything to fix errors in contacts added manually, it’s done a good job for me.

Client-side stuff can be terribly specific to a device and versions of the app and operating system. We tend to stay away from this level of detail about mobile apps in the Office 365 for IT Pros eBook, but we like the ability to publish stuff like this here.

For Both Teams and Skype for Business Online Meetings

In May, Microsoft published Office 365 notification (MC213856) to say that OWA and Outlook Mobile would soon make online meetings the norm. This is now the case.

The calendar settings for OWA include whether an online meeting should be created for all meetings (Figure 1). By default, the setting is controlled by the OnlineMeetingsByDefaultEnabled setting in the Exchange Online organization configuration, which can be examined using the Get-OrganizationConfig cmdlet. Here we see that the setting is true, meaning that all meetings created by OWA are online:

Get-OrganizationConfig | Select OnlineMeetingsByDefaultEnabled

OnlineMeetingsByDefaultEnabled
------------------------------
                          True

Mailbox-Level Control

You can also control the setting on a mailbox basis by updating its calendar configuration with the Set-MailboxCalendarConfiguration cmdlet. The mailbox-level setting takes precedence over the organization setting. For example, this command disables online meetings by default for a mailbox:

Set-MailboxCalendarConfiguration -Identity James.Joyce –OnlineMeetingsByDefaultEnabled $False

OWA uses the Teams configuration to figure out if Teams or Skype for Business Online is the current provider of online meetings to the tenant. The provider is noted in the calendar configuration of each mailbox. We can check which provider is used by running code like this to report the provider and if online meetings are enabled. Fetching calendar configuration can take some time to complete for more than a few mailboxes:

$Mbx = Get-ExoMailbox -RecipientTypeDetails UserMailbox -ResultSize 50
$Mbx | Get-MailboxCalendarConfiguration |Select Identity, DefaultOnlineMeetingProvider, OnlineMeetingsByDefaultEnabled

Identity       DefaultOnlineMeetingProvider OnlineMeetingsByDefaultEnabled
--------       ---------------------------- ------------------------------
Andy.Ruth      TeamsForBusiness
Ben Owens      TeamsForBusiness
Ben.James      TeamsForBusiness
Brian Weakliam TeamsForBusiness
Imran Khan     TeamsForBusiness
James.Joyce    TeamsForBusiness             False
Kim Akers      TeamsForBusiness             True

Different Approach Used by Outlook Desktop

Outlook desktop takes a different approach to OWA. Outlook doesn’t use the calendar configuration settings stored in user mailboxes; its settings are in user profiles stored in the system registry. Currently, Outlook doesn’t have a setting to control whether all meetings should be online and instead loads an add-in to allow users to decide if a meeting should include Teams or Skype for Business Online.

When you create an online meeting, Outlook populates several properties for the meeting item stored in the mailbox containing links and other information about the online space for the meeting. The link allows users to join the online meeting at the appointed time. Apart from the link and the list of meeting attendees, Outlook has no connection to the online event, so items such as the meeting chat, participant list, and so on must be accessed through the online provider.

Microsoft 365 Roadmap item 58132 promises that Outlook for iOS will allow third-party online meeting providers like Zoom and WebEx to be the preferred provider. Microsoft was supposed to deliver the capability in August 2020, but there’s no sign of it still.

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API in Preview Revealed at Ignite 2020 Conference

The advent of support for roaming signatures for Outlook desktop caused some to question if the case to use third-party email signature management products had weakened. As it turned out, Microsoft delayed the deployment and the latest information published in Office 365 notification MC215017 on September 22 says:

• We will begin rolling this out to Microsoft 365 Monthly Channel, Targeted, in late September (previously July). (This is Insiders Slow Channel which will soon be called Microsoft Beta.)
• We expect to roll this out to the Monthly Channel, Production, in late October (previously August).

Update: According to Microsoft 365 roadmap item 60371, the latest date for the general availability of roaming signatures is July 2022.

Not Easy to Manage Outlook Signatures

My experience of using PowerShell to create and update signatures for Outlook desktop convinced me of the complexity of the task. By comparison, the signatures used by OWA are much easier to manipulate. Messages generated by Outlook mobile and other email clients connected to Exchange Online are typically handled by routing the email through an Azure-based cloud service and then back to Exchange Online for onward delivery. In a nutshell, managing corporate email signatures is not easy, especially when multiple client types are involved.

A New Signature API for ISVs

Still, ISVs need to improve their software to convince potential customers that it’s best to use their products instead of relying on what Microsoft delivers. What might surprise some is that Microsoft helps ISVs, as evident in the Build Outlook Add-ins that integrate your solution seamlessly into your users’ Outlook experience session​ (yes, that’s a mouthful) from Ignite 2020.

The session features Szymon Szczesniak, the genial CEO of Code Two software (Figure 1), discussing his company’s experience of using a new Signature API to create web add-ins which work for Outlook desktop (Windows and Mac) and OWA (now), and Outlook mobile (in the future).

As you might expect, Code Two created a web add-in to add a corporate signature to a message before it is sent. This has been possible in the past, but only by creating something like a COM add-in that had to be installed on individual workstations or distributed to sets of workstations using Group Policy Objects. The COM add-in worked by updating Outlook settings with the signature, which Outlook then applied to new messages.

What’s Possible with Signature Web Add-ins

The Signature API and web add-ins are a dramatic step forward. Signatures inserted by add-ins based on the API can be dynamic, meaning that they can be intelligent enough to detect the type of message to insert an appropriate signature. For instance, a new message might get the full treatment with a corporate slogan inserted along with user details while a reply or forward might have a cutdown signature inserted or none. If the company publishes multiple types of signature available (for instance, signatures with different graphic layouts), users can select which they’d like to use.

Finally, because the processing is done on the client before email is sent, protection applied by sensitivity labels or Office 365 message encryption works properly and solve the issues highlighted in this article, at least for Outlook clients. Challenges remain for dealing with mail traffic generated by Outlook mobile (until it supports the web add-ins) and non-Microsoft email clients, which will still need to be processed en route.

Expect December Developments

Although Code Two Software get the kudos for publicizing the new Signature API, they won’t be the only ISV to exploit the API (LetsSignIt announced that they have also been working with Microsoft to develop an add-in). I expect a batch of new products and offerings to appear soon after Microsoft makes the API generally available, expected before the end of this year. Overall, the new API will make email signature management easier to deploy and manage, and that can’t be a bad thing.

Update March 22, 2021: Code Two has released their “modern web add-in” for Outlook and OWA. Like many software developments, it took a little longer to get the add-in from early development to full production.

Update May 25, 2021: Announced at the Build 2021 conference, Code Two Software’s modern signatures add-in for OWA and Outlook for Windows is now generally available. Not to be outdone, Exclaimer has support for an OWA add-in too (but not Outlook desktop yet). Expect all the major email signature vendors to follow suit in the near future.

We don’t cover much about ISV software in the Office 365 for IT Pros eBook. In this case, email signature management has been such a pain for so many organizations for so long that we’re delighted to see progress in the space.

Outlook Mobile Is So Much Nicer Than Those Other Clients…

Office 365 Notification MC207028 posted in March announced that users in some markets would see a notice in OWA to tell them that their license covers Outlook Mobile and they can get Outlook on their phone. Microsoft released MC219490 on July 29 to say that the change now applies worldwide, except to government cloud users. I hadn’t seen this before because Microsoft had excluded European Union customers up to now.

MC207028 says: “Many customers are not aware they can get additional functionality and commercial use rights to Outlook mobile as part of their Office 365 and Microsoft 365 services at no extra cost.” This is probably true, but the real meaning of the message is “Hey stupid! Why would you ever use anything but Outlook Mobile to connect to Exchange Online” (said in a much nicer way).

The plan is to start showing notices in OWA and progress to Outlook desktop in the future. If users dismiss the notice it won’t reappear. If they decide to action it, they’ll get a link or scannable code to download Outlook Mobile.

Undoubted #1 Mobile Client for Exchange Online

There’s no doubt that Outlook Mobile is the premier mobile email client for Exchange Online. Apart from supporting the widest degree of email functionality available to any mobile client, Outlook mobile includes deep integration with other components of the Microsoft 365 ecosystem, including Microsoft Search, Microsoft 365 Groups, and OneDrive for Business.

Over the last year, Microsoft has added features like support for sensitivity labels, shared mailboxes, and delegate access to increase the functionality gap with other email clients, like the native mail apps bundled with iOS and Android. These clients use Exchange ActiveSync (EAS) to communicate with Exchange Online, and although EAS was a solid connectivity protocol ten years ago, it has aged badly recently. The simple fact is that EAS will never support the necessary API calls to allow third-party mobile mail clients to attain feature parity with Outlook Mobile. Soon you’ll be able to make Outlook Mobile the default email client for iOS 14, but that doesn’t mean that everyone needs to use Outlook Mobile.

Personal Choice

Personal choice is important. In April 2019, Microsoft said that over 100 million people used Outlook Mobile. At that time, Office 365 has 185 million active users. That figure is closer to 270 million today (my estimate) and the growth in the Outlook Mobile base probably tracks Office 365 closely. Even so, some people choose to use EAS- or IMAP4-based clients. This might be because they prefer how those clients work or they like a specific feature, such as the ability to connect to accounts in multiple Office 365 tenants, which is something Outlook Mobile currently can’t do.

It’s reasonable for Microsoft to make tenants aware that Outlook Mobile is included in their licenses, but you’ve got to question why they feel the need to highlight this to end users. From a customer perspective, this is a bad idea. It will cause end users to ask why they see the message and what they should do; it might generate extra demand for support services, and it’s yet another example of Microsoft seeking to communicate directly with end users.

Disabling Outlook Mobile Notices with MobileAppEducationEnabled

Fortunately, Microsoft has provided a way for tenants to suppress the notices with a simple update to the Exchange Online organization configuration to set the MobileAppEducationEnabled switch to $False.

Set-OrganizationConfig -MobileAppEducationEnabled $False

The name of the switch is indicative of a feeling that Microsoft needs to educate the Office 365 user base about the goodness of Outlook Mobile. It would be better if Microsoft concentrated on developing functionality that solved real problems for customers instead of pushing their software through all possible means.

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News via Twitter Reveals New Editor

A February 26 tweet from the redoubtable Ross Smith IV reveals that Microsoft has given Outlook for iOS a new rich text editor.

Welcome as the news is, it came as surprise because Microsoft didn’t issue an Office 365 notification. The feature is listed as Microsoft 365 roadmap item 54805 “rich text options” with a “rolling out” status. There’s no word (and no roadmap item) to say if Outlook for Android will receive similar capabilities.

New Editor Brightens Outlook for iOS Messages

In any case, although you won’t be tempted to write the next great chapter of your book with Outlook’s text editor, this is a nice step forward that allows senders to highlight and emphasize important points in their messages.

When you compose a new message, the rich text editor is accessed by clicking the A/pencil icon in the menu bar just above the keyboard. You can then apply three styles to text (body, subhead, and title), create bulleted and numbered lists, add clickable web links, and make text italics, bold, underlined, or a combination (Figure 2).

Of course, a new text editor won’t do anything to improve the quality of your writing, but the text might look more attractive than the simple formatting used to date.

The screen shot was taken using Outlook for iOS 4.27.0 (available in TestFlight). No doubt the new editor will land on a device close to you sometime soon.

Baffled by the blizzard of changes in Office 365? Subscribe to the Office 365 for IT Pros eBook and let us track updates for you.

Using Delegate Permissions to Manage Mailboxes

Office 365 Notification MC203923 published on Valentine’s Day gives the welcome news that Outlook mobile clients are gearing up to be able to use the Exchange Online delegate permissions to manage another user’s mailbox. This work builds on the shared mailbox support delivered for Outlook mobile last August. The net is that Outlook Mobile Delegate Access for Exchange Online mailboxes is now available.

The associated Microsoft 365 roadmap items (53666 for iOS and 53667 for Android) are somewhat obscure in what they say: “Delegates can access and manage messages within an owner’s inbox folder.” This is what shared mailbox support is all about. Fortunately, the notification is more helpful when it tells us that: “Delegates who have been granted full access permissions to send email and respond to calendar invitations on the behalf of another person will soon be able to do so from Outlook for iOS and Android.” Delegate access is described in this Microsoft support article.

Deployment Done by mid-April

Microsoft says that they are deploying the feature now. The minimum supported versions are Outlook mobile 4.25.0 for iOS (available in Testflight) and Outlook mobile 4.1.31 for Android. As always with Outlook mobile features, it takes a little time to get the new software everywhere. Microsoft says that worldwide deployment should be done by mid-April.

Full Access Permissions Needed

Delegate access only works when the user and the delegate both have Exchange Online mailboxes. The delegate must be assigned full access permission for the target mailbox before Outlook mobile can add it as a delegate mailbox. Permission is granted by editing the mailbox with the Microsoft 365 Admin Center. Open the mailbox properties and select the manage mailbox permissions tab. Then add the user to whom you want to grant access. Figure 1 shows the assignment of Full Access permission, referred to by the Admin Center as “Read and manage permission.”

Alternatively, run the Add-MailboxPermission PowerShell cmdlet. This example gives James Ryan full access to the mailbox owned by Kim Akers. The automapping parameter is set to false to stop Outlook desktop including the mailbox in the set of resources automatically opened by the client.

# Add full access permission to mailbox but don't automap
Add-MailboxPermission -Identity Kim.Akers -AccessRights FullAccess -User James.Ryan@Office365itpros.com -AutoMapping $False

Full Access grants a delegate the ability to open the mailbox and interact with its content. It grants the delegate access to every folder, meaning that they can manage the calendar. The delegate can also read every message in the mailbox. Outlook mobile doesn’t use the set of granular folder-level permissions supported by Outlook desktop to grant delegate access to specific folders.

Permission to Send Email Needed Too

Full Access doesn’t allow a delegate to impersonate the mailbox owner when sending messages. A second permission is needed, and the delegate needs to be assigned either Send On Behalf or SendAs permission. These permissions can be added through EAC or by running the Add-MailboxRecipientPermission (SendAs) or Set-Mailbox (Send On Behalf) cmdlets. For example:

# Add permission for a user to send as another user
Add-MailboxRecipientPermission -Identity Kim.Akers -AccessRights SendAs -Trustee James.Ryan
Set-Mailbox -Identity Kim.Akers -GrantSendOnBehalfTo James.Ryan

It takes a few minutes to ensure that the new permissions are fully respected across Office 365.

Adding the Mailbox to Outlook Mobile

Open Outlook mobile and go to the Settings section. Select Add Email Account and then Add Shared Mailbox. Input the SMTP address of the mailbox you want to add. If your account has delegate permissions for the mailbox, Outlook mobile lists it in the set of mailbox resources accessible in the client (Figure 2).

You can also add a delegate mailbox from the list of mailboxes displayed by Outlook mobile (left-hand navigation) by selecting the mailbox add icon at the bottom of the list.

Processing Email

After adding the delegate mailbox, you should be able to see all the folders in the mailbox including the calendar. You can interact with any of the messages in the delegated mailbox as if you are the owner, meaning that you can delete messages, move them between folders, and so on.

To send a message, click the New message icon and compose the message ad normal. The name of the mailbox being used is displayed under the New Message label (Figure 3). Note that in this case my signature is included in messages created for the delegated mailbox.

If you’re using delegate mailboxes, you’ll want to create a separate signature for each mailbox. Do in Settings by selecting Signature and then enabling per-account signature. You can then enter a signature for each account.

Another way to send from a delegated mailbox is to compose a message and then select the mailbox to use from the drop-down list of accounts under the New Message label (Figure 4).

Delegate Access is Another Reason to Use Outlook Mobile

Adding functionality like delegate access to mailboxes underscores the advantage of using Outlook mobile with Exchange Online compared to clients based on the ActiveSync protocol. ActiveSync is a very successful protocol that helped Microsoft evangelize mobile connections to Exchange across a wide range of email clients, but it’s an aging protocol now and just doesn’t have the same functionality as the newer Microsoft sync technology. If you’re not using Outlook mobile now, maybe now’s the time to consider switching?

The Office 365 for IT Pros eBook covers clients in some detail, including how delegate access works. It’s another reason why you should be a subscriber.

Do Not Disturb Feature Now Enabled for Office 365 and Outlook.com Accounts

Some news from Microsoft reveals that Outlook for iOS now supports the Do Not Disturb feature that its Android counterpart has had since July 2018. The delay in bringing the feature to iOS is curious and is perhaps associated with some difficulties manipulating the Apple notification service, something that Teams managed with its Quiet Hours feature in November. Microsoft says that Do Not Disturb can be set for Outlook for iOS by any Office 365 or Outlook.com account.

The idea is similar: to set times when you don’t want notifications for an app to arrive on your device. In the case of Outlook, a reasonable set of options are available to disable notifications indefinitely, for an hour, until the next day, for for some predefined periods like the work day or weekends (Figure 1).

Setting Do No Disturb for Outlook

Setting Do Not Disturb is straightforward. Go to the Home menu to view the set of accounts configured for Outlook. Now select which account for which you want to set Do Not Disturb. Or, if you want to set Do Not Disturb for all accounts, click the Home icon. Now select the alarm bell icon to define the notification block period. In Figure 2, you can see that three accounts are configured for Outlook and all the accounts are set to Do Not Disturb.

Click the alarm bell to change or disable the settings. For example, you might decide to silence some accounts and keep others active when you expect some high-priority messages to arrive.

Play My Emails and Time to Leave Both Need Cortana

Outlook mobile has been on a roll in terms of introducing new features recently. However, it’s not good that some of the more interesting features in Outlook are currently confined to the U.S. with no information available when they might become available elsewhere. Play My Emails, which allows Office 365 users to have their email read to them and to respond with voice commands, and Time to Leave, which prompts users when they need to leave their current location to be on time for a meeting, are both only available in the U.S. Or, as Microsoft says in the original announcement about Time to Leave in December 2017, markets where “Cortana is available.”

Microsoft made a big thing of the Play My Emails feature at the Ignite 2019 Conference. Customers were offered the chance to ride an exercise bike while processing their inbox, an activity that raised several thousand dollars for charity. A more normal example might be to process messages while driving into work, in countries where this kind of mobile usage is allowed. Duly impressed (with the technology, not the exercise), I asked the Outlook team why my account didn’t support the feature (Figure 3) only to discover that Play My Emails requires Cortana to be available in the Office 365 datacenter region hosting your mailbox. The three accounts listed here are an Office 365 account, an Outlook.com account, and a shared mailbox.

The same underlying problem appears to block the ability of non-U.S. Outlook accounts to be notified by Time to Leave, a service also powered by the elusive Cortana.

Configuring iOS to be in the U.S. or setting the location for your Office 365 account to be in the U.S. isn’t enough to trick Cortana that she can process your email or help you get to meetings on time. The availability of the features is dependent on where your mailbox runs. In my case, it’s the Western Europe datacenter region where the active copy of my mailbox might be in Dublin, Amsterdam, Vienna, or Helsinki, depending on how Exchange Online feels like on the day in question.

It’s great to see new technology coming through in mobile devices, but it’s sad when Microsoft’s vaunted campaign to make increased use of artificial intelligence and machine learning is incapable of supporting features outside the U.S. Much as it pains me to say this, there is a world outside Redmond…

For more coverage and information about Office 365 clients, read the chapter in the Office 365 for IT Pros eBook.

Protect Sensitive Email From Your iOS or Android Device

Office 365 notification MC193643 published on October 22 brings the good news that Outlook for iOS and Android has started to roll out native support for Microsoft 365 Sensitivity Labels. The update fulfills Office 365 roadmap items 32648 (iOS) and 32649 (Android). Support for sensitivity labels is available in Outlook for iOS 4.7.1 (which is what I tested) and Outlook for Android 4.0.39.

Native support means that you can protect messages created in Outlook mobile by applying any of the Office 365 Sensitivity Labels published to your account via a label policy. Outlook Mobile clients have long been able to read protected content; this change adds the ability to apply protection (encryption) on the device.

Support For Sensitivity Labels Gradually Spreading

OWA recently got native support as did the Office ProPlus desktop applications. The remaining outliers are the Office Online apps and the SharePoint Online and OneDrive for Business browser interfaces. Sensitivity labels and policies are managed in the Security and Compliance Center.

Protecting Sensitive Email with Outlook for iOS

To apply an Office 365 Sensitivity Label to a new message, click the […] menu when composing the message and select Add Sensitivity (or Edit Sensitivity if you want to change the assigned label).

Next, select the sensitivity label to apply to the message (Figure 2). You can select any of the labels published to your account. Some labels apply markings (like headers) to messages while others encrypt the content using a Rights Management Template. The labels with a padlock icon apply encryption.

After applying a label, you continue to finalize the text and send the message. In Figure 3 we can see that the assigned label will encrypt the message because a padlock icon is present.Labels used for marketing have a stamp-like icon (not a postage stamp).

Where Encryption Happens

Unlike Outlook desktop or OWA, the Outlook mobile clients do not encrypt protected messages on the device. Instead, the message passes to the Exchange Online transport service where the label is detected and encryption, if needed, is applied prior to recipient delivery. Any attachments for labeled messages receive the same level of protection.

Exchange Online uses the same approach to decrypt protected content before delivery to mobile devices.

S/MIME Support Too

Microsoft also announced (MC193642) the general availability of S/MIME support for Outlook Mobile. Although Office 365 Sensitivity Labels can protect email and documents for Office 365 users, including when items are sent outside the tenant, S/MIME is sometimes preferred because it is an Internet protocol or because an organization has invested in the certificate infrastructure for S/MIME. The good thing is that Office 365 users can now choose either approach to protect confidential information. See this link for more information about the two methods for email protection.

Office 365 Sensitivity Labels are covered in detail in the Office 365 for IT Pros eBook. Subscribe now to stay updated with developments across Office 365.

Filtered Email Views for Your Most Important Contacts

Over the years, Microsoft has made many attempts to help people access Inbox contents more intelligently, mostly by applying views to isolate and highlight important messages. The Clutter feature appeared in 2014 only to be replaced by the Focused Inbox in 2016. Now we have Outlook People Favorites.

Favorites have been around for years. Folder favorites give fast access to the most important parts of a user’s mailbox while favorite categories allow users to find messages tagged in particular categories. Outlook does this by creating a view within the mailbox to find all messages in the selected category. People favorites are like categories in that when you add someone (an email address) as a favorite, Outlook creates a view to find all messages from that person. It’s as simple as that.

Creating and Managing People Favorites

People favorites are designed to give quick and simple access to messages from those who are important to you, like your direct manager or critical customers. To mark someone as a people favorite, use OWA to select a message where they are a recipient or sender and click their email address to expose their people card. In Figure 1, I’ve selected David Los, who works on OWA (seems appropriate). To make David one of my people favorites, I clicked the star beside his name in the people card.

You can manage the set of people favorites through OWA’s People section. People and Groups are managed together (Figure 2). Favorite categories are managed through OWA options. To remove someone from the set of people favorites, deselect the star opposite their name.

Behind the scenes, Exchange Online creates a folder in the non-IPM section of the mailbox to hold pointers to items relating to the favorite. The folder is stored under the FavoritePersonas root. We can see details of the folders by running these PowerShell commands:

$Folders = Get-ExoMailboxFolderStatistics -id mailboxi-id -FolderScope nonipm -IncludeOldestAndNewestItems | Select Name, Itemsinfolder, NewestItemReceivedDate, FolderPath
$Folders | ?{$_.FolderPath -Like "*FavoritePersonas*"}|  sort  {$_.NewestItemReceivedDate -as [datetime]} -desc | Format-Table ItemsInFolder, Name

ItemsInFolder Name                                                   NewestItemReceivedDate
------------- ----                                                   ----------------------
          209 James Redmond_b4b30d32-ba9a-4d9b-ad76-7bdb3b6b6c51     09/12/2019 15:20
          222 Thomas Bowers_6701c170-5c66-4ded-ac00-5e083d2ab648     03/12/2019 14:33
           37 Mary-Jo Smith_589ac9ce-da38-45e2-b2b4-24950fb1c270     05/12/2019 09:55
           59 Brad Jones_9607102f-465a-48d9-846b-a3dd7cb9cdb8        01/11/2019 11:00
           40 David Los_078e789e-fa0a-4e98-bb83-ca81ff9a54ca         07/11/2019 23:15
            0 Steven Phillips_9a81d5c0-055e-400e-a0cb-9b43e21c93e7

The items in the persona folders are not updated in real-time. Instead, a background mailbox assistant processes the mailbox to find matching items and creates items for display when the favorite is accessed. The items in the favorite folder might therefore be a little behind. The folder listed above with zero items is just added and hasn’t yet been processed by the assistant.

Using People Favorites

People favorites show up in the set of resources available to OWA users, just like favorite folders and categories. In Figure 3, you can see that my favorites include some categories, groups, and people. Because Exchange Online generates views for favorites, we see unread counts for groups and people where unread messages exist in the mailbox. Selecting a people favorite displays the messages from that person inside the mailbox.

Mobile People Favorites

OWA boasts the most complete implementation but the favorites also appear in Outlook mobile. Figure 4 shows how people favorites appear in Outlook for iOS. You can also create new people favorites in Outlook mobile, but although the favorite is created I have found that Exchange Online sometimes doesn’t generate the view, so when you select the favorite created in Outlook mobile, you see no messages.

Outlook mobile clients don’t use the hidden mailbox folders to reveal items for about people favorites. Instead, these clients search the mailbox and synchronize items on an on-demand basis, an implementation which is more in line with the synchronization model used to update folders for other Outlook mobile resources.

No People Favorites for Outlook Desktop

Outlook desktop doesn’t support people favorites. This isn’t surprising. The Outlook desktop UI is notoriously difficult to change, which is why features that need UI updates invariably appear in OWA and Outlook mobile first.

Need help to keep track of changes in Office 365? It can be really hard to track small but important changes in client user interfaces, which is why Office 365 for IT Pros can help. We’ve been tracking changes like this for six years and are pretty good at it by now.

Outlook Mobile Shared Mailboxes in IOS and Android – Sharing is Caring!

August 29 note: The current versions of Outlook mobile include support for shared mailboxes. See this post for details or read on to learn how to add shared mailboxes to Outlook mobile.

Last week, we learned that Microsoft will soon roll out support for shared mailboxes in Outlook Mobile. Well, some people already have access to the feature through Apple’s Testflight for iOS program. Testflight allows developers to offer test versions of applications like Outlook mobile to people who don’t mind running beta software. The upside is that you see new features sooner. The downside is that the new features might not work or might change before the final version is released. With those caveats in mind, let’s explore how to add a shared mailbox to Outlook mobile using Testflight version 3.27.0.

Add Shared Mailboxes to Outlook Mobile

Before you can add a shared mailbox to Outlook mobile, you should meet these criteria:

• The shared mailbox must already exist on Exchange Online. Outlook mobile can only access existing shared mailboxes; it can’t create a new shared mailbox.
• Your primary mailbox must be in Exchange Online. Users in a hybrid organization whose mailbox is on-premises can’t add shared mailboxes to Outlook mobile.
• Your account has access to the shared mailbox. This means that an administrator assigns your account full access to the shared mailbox. In addition, if you want to send from Outlook Mobile as the shared mailbox, your account must hold SendAs permission for the mailbox.
• You must know the primary SMTP address of the shared mailbox. Why? Because you need to input the mailbox’s SMTP address when you add the shared mailbox.

With everything in place, go to the list of resources available to Outlook mobile and click the + icon and then choose Add Shared Mailbox (Figure 1).

Now input the primary SMTP address of the shared mailbox and click the Add Shared Mailbox button.

That’s all you need to do. Outlook Mobile adds the shared mailbox to its resource list and you can access the contents like any other mailbox.

One big benefit of native support in Outlook mobile for shared mailboxes is that it removes the need for people to use outdated protocols like IMAP4 to access shared mailboxes. From a Microsoft perspective, it gives customers another good reason to move to Outlook mobile and away from apps like the native iOS mail app that use the Exchange ActiveSync protocol to interact with mailboxes (ActiveSync doesn’t support shared mailboxes, which is why people end up using IMAP4).

Outlook Insiders and Testflight

If you want to test shared mailboxes with Outlook Mobile now, you can sign up for the Outlook Insiders program (limited slots are available). You’ll also need to download and install Testflight from the iOS app store. You can then download the test version of Outlook.

One side effect of using the test version is that Office 365 automatically provisions your tenant to use the Microsoft Sync Technology (if it didn’t, you wouldn’t be able to test new features). This process takes about 24 hours. When it’s done, you’ll be able to add shared mailboxes to your heart’s content, but only with iOS clients for now. According to a tweet from Outlook Mobile development last Friday, support for Android is coming “soon.”

Need more information about Office 365 clients, including Outlook Mobile? Read the Clients chapter in the Office 365 for IT Pros eBook!

Removes Need for IMAP4 Workaround

Office 365 notification MC181641 posted on June 5 includes the good news that Outlook mobile (iOS and Android) will soon support connections to Exchange Online shared mailboxes. This will remove the need for the IMAP4 connection currently used as a workaround to access shared mailboxes. Apart from the general kludginess of the IMAP4 workaround, if you log onto a shared mailbox with IMAP4., that mailbox should technically have an Office 365 license.

The development also addresses a huge feature gap that Microsoft has acknowledged to exist for years. This update relates to Office 365 Roadmap items 32571 (iOS) and 32572 (Android) and not the two listed in the announcement.

The announcement says: “You will be able read, write and send emails from the Exchange Online Shared Mailboxes in Outlook for iOS and Android. If you are part of the Office Insider program for iOS and using the Microsoft sync technology (MC165218), you will be able get an early preview of the capabilities via TestFlight this week. It is anticipated that we will start to roll out Shared Mailboxes in Outlook for iOS and Android (using Microsoft sync technology) for general availability in the next several weeks.”

In other words, expect to see shared mailbox support appear in July 2019. That is, if support for the Microsoft Sync Technology is deployed to your Office 365 tenant. To check, look at the settings for your account (Figure 1), or use the PowerShell script in this article.

Microsoft Sync Technology is the new connection protocol for Outlook mobile clients that Microsoft has deployed to Outlook.com and the Government Cloud (GCC) and is now rolling out to commercial tenants. Hopefully, the advent of shared mailbox support serves as a spur for Microsoft to complete the deployment of the new sync technology.

Updated Files, Calendar Events in Search, and Calendar Sync

Microsoft includes some other updates in MC181641. These are:

• Updated Files: The way Outlook mobile presents files will become more coherent with the rest of Office 365 and include a list of recently used files plus cloud sources (like OneDrive for Business or Google Drive). You’ll be able to add a link to share a file that complies with default tenant sharing permissions.
• Calendar Events in Search: When you search for someone or use a keyword, the results returned will include any matching events found in your calendar. This feature also depends on Microsoft Sync Technology.
• Calendar Sync: Outlook for Android now supports syncing calendar events from the native calendar app. This is a one-way sync and Microsoft says that the ability to sync from Outlook to local calendar apps is still in development.

Lots Happening in Mobile

Mobile apps tend to evolve quickly. Outlook mobile is no different. These changes, particularly shared mailbox support, will make many people very happy.

Need more information about Outlook clients? Or Office 365 clients in general? We have a complete chapter on the topic in the Office 365 for IT Pros eBook.

Outlook Mobile Connects with Microsoft Sync Technology or an Older Protocol

In my Petri.com article about the new architecture (aka, “Microsoft Sync Technology”) Microsoft is deploying to connect Outlook for iOS and Android devices to Exchange Online and Outlook.com, I mention a Microsoft FAQ on the topic. That FAQ includes some PowerShell code to help administrators know what protocol devices use to connect. The code is perfectly good, but being PowerShell, there are many ways to approach a problem and some to improve the solution. Here’s my attempt to do so.

The single-line command (always good) in the FAQ uses the Get-MobileDevice cmdlet to retrieve a list of devices that have connected to Exchange Online, extracts the devices running the iOS or Android client, and reports the protocol each device uses. All good, but the data would be more valuable if you knew who used the devices as well.

Mailboxes, Not Mobile Devices

My solution takes a user-centric approach to the question. The first step to know who is using Outlook for iOS or Android to connect to Exchange Online is to create a set of user mailboxes as they’re the only Exchange objects that can have mobile devices.

Next, we go through the list of mailboxes and use the Get-MobileDeviceStatistics cmdlet to examine details of mobile devices that have “partnerships” with each mailbox. We’re only interested in devices that report running Outlook for iOS or Android. If we find such a device, we grab the statistics like the O/S version running on the device and the date and time of the last successful synchronization. To know what architecture the device uses, we examine the ClientType property, which is “REST” if the device connects using the old architecture, or “Outlook” for the new.

[array]$Mbx = (Get-ExoMailbox -RecipientTypeDetails UserMailbox -ResultSize Unlimited | Select-Object Alias, DisplayName)
Write-Host "Processing" $Mbx.count "mailboxes"
$Report = @()
ForEach ($M in $Mbx) {
   Write-Host "Checking devices for" $M.DisplayName
   $Devices = (Get-MobileDeviceStatistics -Mailbox $M.Alias | ? {$_.DeviceModel -eq "Outlook for iOS and Android"})
   If ($Devices.Count -eq 0)
      { Write-Host $M.DisplayName "has no Outlook Mobile devices"}
   Else 
      { ForEach ($D in $Devices) {
        $ReportLine = [PSCustomObject]@{
           User     = $M.DisplayName
           Device   = $D.DeviceFriendlyName 
           OS       = $D.DeviceOS
           SyncType = $D.ClientType
           LastSync = $D.LastSuccessSync}
      $Report += $ReportLine }
  }
}

Examining Connection Details

To see what data our code generates, we examine the $Report variable.

$Report | Format-Table User, Device, SyncType, Lastsync, OS

User            Device          SyncType LastSync             OS
----            ------          -------- --------             --
Deirdre Smith   Outlook for iOS REST                          iOS 12.1
Deirdre Smith   Outlook for iOS REST     24 Aug 2018 17:30:53 iOS 11.4.1
Deirdre Smith   Outlook for iOS REST     4 Dec 2018 21:27:16  iOS 12.0
James Ryan      Outlook for iOS REST     10 Oct 2018 16:22:52 iOS 12.0
Tony Redmond    Outlook for iOS REST     1 Oct 2017 18:13:27  iOS 10.3.3
Tony Redmond    Outlook for iOS REST     4 Dec 2018 22:32:34  iOS 12.0

At the time of writing, clients in my tenant still use the REST protocol that’s soon to be replaced by the Outlook protocol. See the Petri.com article for details.

Of course, if we need to do some deeper analysis, we can output the information to a CSV file with another command. The CSV file can then be loaded into Excel or Power BI to slice and dice the data, generate graphs, and so on.

$Report | Export-CSV -NoTypeInformation c:\temp\OutlookMobileDevices

Easy!

For more information about Office 365 clients, read Chapter 10 of the Office 365 for IT Pros eBook, while Chapter 18 covers mobile devices.