Microsoft Outlook is an anchor app within the Microsoft 365 productivity suite. Microsoft 365 is a cloud-based collaboration platform that includes a suite of products, accessible via one convenient login, that caters to small businesses and entrepreneurs. Outlook.com is a free web-based e-mail service provided by Microsoft. It’s somewhat like Google’s Gmail service but has a twist — a link to your desktop Outlook data. Microsoft has combined Hotmail and Windows Live into one e-mail service, and has added support for contacts (including Facebook, Twitter, and LinkedIn) and your calendar.

• What Does Flagging A Message In Outlook Do
• What Is Outlook
• What Is Outlook Microsoft

Original KB number: 2652320

Symptoms

When you open a file or send an email message in Microsoft Outlook 2010 or later versions, Outlook freezes, or you receive the following error message:

Outlook not responding

Cause

This problem occurs for one or more of the following reasons:

• You have not installed the latest updates.
• Outlook is in use by another process.
• Outlook is loading external content, such as images in an email message.
• A previously installed add-in is interfering with Outlook.
• Your mailboxes are too large.
• Your AppData folder is redirected to a network location.
• You have to repair your Office programs.
• Outlook data files have become corrupted or damaged.
• Your installed antivirus software is outdated, or it conflicts with Outlook.
• Your user profile has become corrupted.
• Another program conflicts with Outlook.

Note

• This issue may occur for one or more of the reasons in this section. To fix this issue, you may have to follow the troubleshooting steps in the Resolution section.
• Many of these items can be automatically checked by the Microsoft Support and Recovery Assistant (SaRA). To start the automated checks, follow these steps:
  1. Install the Outlook Advanced Diagnostics tool.
  2. Select Run when you are prompted by your browser.
  3. In the report that's generated, review the items on the Issues found tab. For configuration details about Outlook, Windows, and your computer, review the settings on the Detailed View tab.

Resolution

To resolve this problem, make sure that your computer meets the Outlook 2016 system requirements, Outlook 2013 system requirements or Outlook 2010 system requirements.

Note

These steps are provided in a specific order based on commonality and complexity. Follow these steps in the given order.

Step 1 - Install the latest updates

The Office installation on your computer might not be up to date. This might be because Windows Update is not configured on your computer to automatically download and install recommended updates. By installing important, recommended, and optional updates, you can often correct problems by replacing out-of-date files and fixing vulnerabilities. To install the latest Office updates, click the link for your version of Windows, and then follow the steps in the article:

Make sure that the latest updates for Outlook are installed. For more information, see How to install the latest applicable updates for Microsoft Outlook (US English only).

Step 2 - Make sure that Outlook is not in use by another process

Performance may be decreased if you use the Outlook AutoArchive feature or sync to Outlook with a mobile device. This is because these processes can use a large number of resources.

If Outlook is in use by another process, this information is displayed in the status bar at the bottom of the screen. If you try to perform other actions while Outlook is in use, Outlook may not respond. Let the task in process finish its job before you try another action.

Step 3 - Check the problem caused by external content

To resolve this issue, use one of the following methods:

• Prevent Outlook to download external contents. To do this, go to File > Options > Trust Center > Automatic Download, select the following two options:
  • Don't download pictures or other content automatically in HTML e-mail option.
  • Warn me before downloading content when editing, forwarding, or replying e-mail.
• Avoid sending such an email with external source.

Step 4 - Investigate possible add-in issues

Although add-ins can enhance your user experience, they can occasionally interfere or conflict with Outlook. Try to start Outlook without any add-ins running.

How to start Outlook without add-ins

1. Do the following, as appropriate for your operating system:
   • If you are running Windows 8, swipe in from the right edge of the screen, and then tap Search. (If you are using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, and then select Search.) Type Run in the search box, and then tap or select Run.
   • If you are running Windows 10, Windows 7 or Windows Vista, select Start.
   • If you are running Windows XP, select Start, and then select Run.
2. Type Outlook.exe /safe, and then select OK.
3. If the problem is resolved, select Options on the File menu, and then select Add-Ins.
4. Select COM Add-ins, and then select Go.
5. Clear all the check boxes in the list, and then select OK.
6. Restart Outlook.

If the problem does not occur after you restart Outlook, one of the add-ins is likely the cause of the problem. Restore the add-ins one at a time until the problem does occur to determine which add-in is causing the problem.

Step 5 - Check whether your mailbox is too large

As your mailbox size increases, more resources are required to open each folder. If you have a large number of items in any single folder, you may experience performance issues during certain operations. For more information, see Outlook performance issues when there are too many items or folders in a cached mode .ost or .pst file.

We recommend that you move several items in your larger folders to separate folders, or that you archive those items by using the AutoArchive feature.

How to create a folder

1. On the Folder tab, select New Folder in the New group.

2. In the Name box, enter a name for the folder.

3. In the Select where to place the folder list, select the location for the new folder.

   Note

   The new folder will become a subfolder of the folder you select.

4. Select OK.

To manage your mailbox by reducing the size of the Outlook data file, see Reduce the size of Outlook Data Files (.pst and .ost).

To manage your mailbox by using the AutoArchive feature, see AutoArchive settings explained.

Step 6 - Check whether your AppData folder is being redirected to a network location

Outlook stores certain data, such as email signatures and the spelling checker dictionary, in the AppData folder. If the network is performing slowly, Outlook must wait for read and write operations to the AppData directory to finish.

How to disable redirection of the AppData directory

1. Exit Outlook.

2. Start Registry Editor. To do this, use one of the following procedures, as appropriate for your version of Windows:

   • Windows 10 or Windows 8: Press Windows Key+R to open a Run dialog box. Type regedit.exe and then press OK.
   • Windows 7: Select Start, type regedit.exe in the search box, and then press Enter.

3. In Registry Editor, locate and then select the following subkey:

   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerUser Shell Folders

4. Locate and then double-click the AppData value.

5. In the Value data box, type the following path, and then select OK:
   %USERPROFILE%AppDataRoaming

6. Exit Registry Editor.

Step 7 - Repair Office programs

You can automatically repair your Office program files to resolve such problems as Outlook freezing or not responding.

How to automatically repair Office

1. Exit any Microsoft Office programs that are running.
2. Open Control Panel, and then open the Add or Remove Programs item (if you are running Windows XP) or Programs and Features (if you are running Windows 10, Windows 8, Windows 7, or Windows Vista).
3. In the list of installed programs, right-click Microsoft Office 2016, Microsoft Office 2013 or Microsoft Office 2010, and then select Repair.

Step 8 - Repair Outlook data files

When you install Outlook, an Inbox repair tool (scanpst.exe) is also installed on your PC. The Inbox repair tool can resolve problems by scanning your Outlook data files, and repairing errors. To use the Inbox repair tool, exit Outlook, and then follow the steps in Repair Outlook Data Files (.pst and .ost).

Step 9 - Check whether antivirus software is up-to-date or conflicts with Outlook

If your antivirus software is not up-to-date, Outlook may not function correctly.

How to check whether antivirus software is up to date

To keep up with new viruses as they are created, antivirus software vendors periodically provide updates that you can download from the Internet. Download the latest updates by visiting your antivirus software vendor's website.

For a list of antivirus software vendors, see Consumer antivirus software providers for Windows.

How to check whether antivirus software conflicts with Outlook

If your antivirus software includes integration with Outlook, you may experience performance issues. You can disable all Outlook integration within the antivirus software. Or, you can disable any antivirus software add-ins that are installed in Outlook.

Important

When you change your antivirus settings, this may make your PC vulnerable to viral, fraudulent, or malicious attacks. We do not recommend that you try to change your antivirus settings. Use this workaround at your own risk.

You may have to contact your antivirus software vendor to determine how to configure the software to exclude any integration with Outlook or to exclude scanning in Outlook.

What Does Flagging A Message In Outlook Do

Note

If you also plan to perform file-level virus scanning of .pst, .ost, Offline Address Book (.oab), or other Outlook files while Outlook is in use, see Plan antivirus scanning for Outlook 2010 or Planning considerations for deploying Outlook 2016 for Windows.

Step 10 - Create a user profile in Outlook

To create a user profile, follow these steps:

1. In Control Panel, select Programs, select User Accounts, and then select Mail to open Mail items.

2. Select Show Profiles.

3. Select the profile that you want to remove, and then select Remove.

4. Select Add.

5. In the Profile Name dialog box, type a name for the profile.

6. Specify the user name, the primary SMTP address, and the password. Then, select Next.

7. You may receive the following prompt:
   Allow this website to configure <alias@domain server> settings?

   In this prompt, select the Don't ask me about this again checkbox, and then select Allow.

Step 11 - Perform a Selective Startup (advanced users)

When you start Windows normally, several applications and services start automatically and then run in the background. These applications and services can interfere with Outlook. A Selective Startup or 'clean boot' process can help you identify problems that are caused by application conflicts.

If you use the Selective Startup option in System Configuration, you can turn services and startup programs on or off individually to check whether the problem occurs the next time that you start your computer. In System Configuration, if you select a check box, the related service or startup program runs when you restart the computer. If the check box is cleared, the service or startup program does not run when you restart the computer.

Follow this procedure to use the process of elimination to identify the problem in Windows 10, Windows 8, Windows 7, or Windows Vista.

Note

For more information about performing a clean boot, see How to perform a clean boot in Windows.

How to do a Selective startup

1. In Control Panel, select System and Security, select Administrative Tools, and then double-click System Configuration.

   Note

   If you are prompted for an administrator password or for confirmation, type the password or provide confirmation.

2. Select the General tab, select Selective startup, and then clear the Load system services and the Load startup items check boxes.

3. Select the Load system services check box, select OK, and then select Restart.

4. If the problem reoccurs after you restart the computer, do one or both of the following tasks, as necessary.

   To determine which system service is causing the problem

   1. In System Configuration, select the Services tab, select Disable all, select the check box for the first service that is listed, and then restart the computer.

      Note

      If the problem doesn't reoccur, then you can eliminate the first service as the cause of the problem.

   2. With the first service selected, select the second service check box, and then restart the computer.

   3. Repeat this process until you reproduce the problem.

      Note

      If you can't reproduce the problem, you can eliminate system services as the cause of the problem.

   To determine which startup item is causing the problem

   1. In System Configuration, select the General tab, and then select the Load startup items check box.

   2. Select the Startup tab, select Disable all, select the check box for the first startup item that is listed, and then restart the computer.

      Note

      If the problem doesn't reoccur, you can eliminate the first startup item as the cause of the problem.

   3. While the first startup item is selected, select the second startup item check box, and then restart the computer. Repeat this process until you reproduce the problem.

Step 12 - Create a Windows user profile (advanced users)

Your user profile is a collection of settings that let you customize the computer appearance and performance. It contains settings for desktop backgrounds, screen savers, sound settings, and other features. User profiles help make sure that your personal preferences are used when you log on to Windows.

To determine whether this problem is caused by a corrupted user profile, create a user profile to see whether the problem still occurs when you use the new profile.

How to repair a corrupted user profile in Windows 8

Step 1 - Create a user account

To create a user profile, you must first create a user account. When the new account is created, a profile is also created.

1. Swipe in from the right edge of the screen, and then tap Search. (If you are using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, and then select Search.) Type Command Prompt in the search box, right-click Command Prompt, and then select Run as administrator.

   Note

   If you're prompted for an administrator password or for confirmation, type the password or provide confirmation.

2. Type net user UsernamePassword /add, and then press Enter.

Step 2 - Copy old files to the new user profile** After you create the profile, you can copy the files from the existing profile

Note

You must have at least three user accounts on the computer to complete these steps. This includes the new account you just created.

1. Log on as a user other than the user that you just created or the user that you want to copy files from.

2. In Control Panel, select Appearance and Personalization, and then select Folder Options.

3. Select the View tab, and then select Show hidden files, folders, and drives.

4. Clear the Hide protected operating system files check box, select Yes to confirm, and then select OK.

5. Open File Explorer. To do this, Swipe in from the right edge of the screen, and then tap Search. (If you are using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, and then select Search.) Enter File Explorer in the search box, tap or select Apps, and then tap or select File Explorer. Type Command Prompt in the search box, right-click Command Prompt, and then select Run as administrator.

6. Locate the C:UsersOld_Username folder, in which C is the drive that Windows is installed on, and Old_Username is the name of the profile that you want to copy files from.

7. Select all the files and folders in this folder, except the following files:

   • Ntuser.dat
   • Ntuser.dat.log
   • Ntuser.ini

8. On the Edit menu, select Copy.

9. Locate the C:UsersNew_Username folder, in which C is the drive that Windows is installed on, and New_Username is the name of the user profile that you created earlier in this method.

10. On the Edit menu, select Paste.

11. Log off, and then log back on as the new user.

Note

If you have email messages in an email program, you must import your email messages and addresses to the new user profile before you delete the old profile. If everything is working correctly, you can now delete the old profile.

Next step

Toss the turtlewatermelon gaming. If the information in this article does not help resolve your problem in Outlook 2016, Outlook 2013 or Outlook 2010, see the following resources for more information:

References

Summary: This article covers the most common questions asked by customers and administrators about using Outlook for iOS and Android with Exchange Online and Microsoft 365 or Office 365.

The Outlook for iOS and Android app is designed to enable users in your organization to do more from their mobile devices, by bringing together email, calendar, contacts, and other files. The following sections highlight the most common questions we receive, across three key areas:

• Outlook for iOS and Android architecture and security

• Managing and maintaining Outlook for iOS and Android in your Exchange organization after it has been deployed

• Common questions from end-users who access information in your Exchange organization with the Outlook for iOS and Android app on their mobile devices

Architecture and security

The following questions are about the overall architecture of Outlook for iOS and Android in Exchange Online, as well as user authentication and other security concerns.

Q: What cloud architecture is utilized by Outlook for iOS and Android for Microsoft 365 or Office 365 accounts?

For more information on the architecture, see Outlook for iOS and Android in Exchange Online.

Q: Can I add two different Microsoft 365 or Office 365 accounts from different regions to Outlook for iOS and Android?

Yes, provided both accounts do not have Intune App Protection Policies assigned. However, for Government Community Cloud customers, users may only add their own account and OneDrive for Business storage account to the app; adding personal or other commercial accounts is prevented to meet FedRAMP requirements. For more information on Government Community Cloud restrictions with Outlook for iOS and Android, please see Using Outlook for iOS and Android in the Government Community Cloud.

Q: What authentication mechanism is used for Outlook for iOS are Android? Are credentials stored in Microsoft 365 or Office 365?

See Account setup with modern authentication in Exchange Online.

Q: Do Outlook for iOS and Android and other Microsoft Office mobile apps support single sign-on?

See Account setup with modern authentication in Exchange Online.

Q: What is the lifetime of the tokens generated and used by the Active Directory Authentication Library (ADAL) in Outlook for iOS and Android?

See Account setup with modern authentication in Exchange Online.

Q: What happens to the access token when a user's password is changed?

See Account setup with modern authentication in Exchange Online.

Q: Does Outlook for iOS and Android support certificate-based authentication?

Yes, Outlook for iOS and Android supports certificate-based authentication for modern authentication-enabled accounts (Microsoft 365 or Office 365 accounts or on-premises accounts leveraging hybrid modern authentication). For more information, see:

Q: What does background synchronization enable? I notice that when I launch the app with it enabled, I still have to wait for messages to download, even after I've received new mail notifications for them; and sometimes, I get reminders for appointments that had been canceled.

Background synchronization enables new message notifications, calendar reminders, badge count updates, and background synchronization of mailbox and calendar information for Outlook for iOS and Android.

If background synchronization is disabled by the user in the mobile operating system's settings, then the user must launch the app and keep it in the foreground in order to synchronize messages and have an up-to-date calendar.

Background synchronization in Outlook for iOS and Android can also be temporarily disabled by the following actions:

• Force quitting Outlook for iOS.

• Restarting the iOS device.

• Outlook for iOS crashes and is not restarted by the user.

• Not opening the app for a given period of time. iOS will automatically freeze third-party apps, like Outlook, based on usage patterns. Android doze mode and app standby features can also prevent background updates to the app while those features are active.

• On some Android devices, you can also restrict background processing or network access per-app. In these cases, Outlook for Android will not be able to process updates in the background. Android device manufacturers can modify the way you can interact with settings, therefore it is not possible to document every device scenario, but in general, these are the steps you can take to remove battery optimization:

  1. Open Settings.

  2. Tap Battery.

  3. Tap the ellipse and tap Battery optimization.

  4. Tap the down arrow and tap All apps.

  5. For the Microsoft Authenticator, Intune Company Portal and Outlook apps, tap Not optimized to turn off battery optimization.

If the mobile operating system prevents background synchronization, users will experience the following:

• New mail notifications will continue to be delivered, however, upon launching the app, the new messages will have to be downloaded.

• Calendar reminders will fire for appointments that have been canceled because the app was unable to download and process the meeting cancellation.

Note

Apple allows its native Mail and Calendar apps to do background refreshes without any restrictions. Therefore, users may notice a difference in the background synchronization experience between the apps. However, this also results in improved battery life and less data consumption with Outlook for iOS.

Q: Does each user's instance of Outlook for iOS and Android have a unique device ID in the Microsoft 365- or Office 365-based architecture? How is the device ID generated and is this same device ID used in Intune?

Upon initial account login, Outlook for iOS and Android establishes a connection to the Microsoft 365- or Office 365-based architecture. A unique device ID is generated, and this device ID is what appears in Active Directory device records (which can be retrieved with cmdlets such as Get-MobileDevice in Exchange Online Powershell) and which appears in HTTP request headers.

Intune uses a different device ID. The basic workflow for how Intune assigns a device ID is described in App-based conditional access with Intune. In Intune, the device ID is assigned when the device workplace joins for all device-conditional access scenarios. This is an AAD-generated unique ID for the device. Intune uses that unique ID when sending compliance information, and ADAL uses that unique ID when authenticating to services.

Q: Does Outlook for iOS and Android support RMS?

Yes. Outlook for iOS and Android supports reading protected messages. Outlook for iOS and Android works differently than desktop versions of Outlook when it comes to RMS. For desktop versions of Outlook, once a protected message is received and access is attempted, and Outlook verifies that the user can read RM messages, Outlook connects to Exchange to request an encryption key. The Outlook desktop client uses that encryption key to decrypt the message in front of the user (client-side). Mobile clients operate differently. When Outlook for iOS and Android sets up its initial relationship with Exchange, it notifies Exchange that it supports RMS. Exchange decrypts any protected messages before passing them to the client. In other words, decryption is performed server-side. Outlook for iOS and Android doesn't perform any decryption itself.

In cases where Outlook for iOS and Android receives protected messages and prompts end-users to use an RM client to open the file, it means that Exchange hasn't decrypted the message, which is due to an issue on the Exchange side.

Note

Outlook for iOS leverages iOS's native preview technology to quickly expose attachments to end users. iOS's preview technology does not support rights management and will report error 'The operation couldn't be completed. (OfficeImportErrorDomain error 912)' when a user attempts to open a rights-protected attachment. Users will need to tap the respective Word, Excel, or PowerPoint app icon to open the rights-protected attachment in the native app.

Q: Does Outlook for iOS and Android support Teams meetings?

Yes, Outlook for iOS and Android supports both Skype for Business and Teams meetings. The Teams coexistence mode at the Microsoft 365 or Office 365 organization level and the user level (the user setting takes precedence over the tenant setting) determines the meeting creation experience in Outlook for iOS and Android:

In addition, for users leveraging the native Microsoft sync technology, a Teams Join button is available in calendar events. This makes it easy to Join a Teams meeting and will be available for all coexistence modes. Users who are not leveraging the native Microsoft sync technology will be able to join Teams Meetings using the weblink in the meeting description.

For more information on the Teams coexistence modes, please see Choose your upgrade journey from Skype from Business to Teams.

Q: What ports and end points does Outlook for iOS and Android use?

Outlook for iOS and Android communicates via TCP port 443. The app accesses various end points, depending on the activities of the user. Complete information is available in URLs and IP address ranges.

Q: Does Outlook for iOS and Android support proxy configurations?

Yes, Outlook for iOS and Android supports proxy configurations when the proxy infrastructure meets the following requirements:

• Supports HTTP protocol without TLS decryption and inspection.

• Does not perform authentication.

Outlook for iOS and Android will consume the proxy configuration as defined by the platform operating system. Typically, this configuration information is deployed via a PAC file. The PAC file must be configured to use hostnames instead of protocol; no additional custom settings are supported. For a list of hostnames that Outlook for iOS and Android accesses, please see URLs and IP address ranges.

For tenants that have not been migrated to the native Microsoft sync technology, the following additional requirement applies:

• Supports and has SOCKS proxy capability enabled. The Outlook for iOS and Android client utilizes TCP connections to our Microsoft 365- or Office 365-based architecture. The IP ranges for the SOCKS connections are not restricted to a subset of Azure IP ranges, which means that customers cannot define a allow list range. The PAC must be configured to use hostnames instead of protocol and return the SOCKS proxy information given the host URL; no additional custom settings are supported.

Q: Does Outlook for iOS and Android support shared mailboxes?

Yes, Outlook for iOS and Android supports shared mailboxes when the user mailbox and shared mailbox are located in Exchange Online and using the native Microsoft sync technology.

A shared mailbox is a special mailbox type that is created using the -Shared parameter. Access to the shared mailbox by a user is obtained via permissions and not through the use of alternate credentials. For more information, please see Shared mailboxes in Exchange Online.

Q: Does Outlook for iOS and Android support delegate mailboxes?

Yes, Outlook for iOS and Android has extended the shared mailbox capability to now allow users to add another person's mailbox when the user has been granted FullAccess permissions to the other person's mailbox. Granting SendAs or Send on Behalf of permissions also allows the user to send messages as the other person's mailbox. For more information on permission assignment, please see Manage permissions for recipients in Exchange Online.

Q: How many accounts does Outlook for iOS and Android support?

Outlook for iOS and Android supports a maximum of 25 accounts.

Q: Does Outlook for iOS and Android support contact management functionality? What about integration with the operating system features?

Yes, Outlook for iOS and Android supports contact management. Within the app, users can initiate phone calls, text messages, video chat (e.g. FaceTime), etc. Integration with the operating system, and contact management functionality, depend on the client platform, where the mailbox resides, and the authentication type used:

For information on consumer accounts, see Outlook's in-app support FAQ on People.

By enabling contact synchronization between Outlook and the native contacts app, users receive the rich experience that the native operating system provides (e.g. inbound and outbound caller-ID, text messaging name resolution, etc.). Only Outlook for iOS should be used for managing contact data and not the native iOS Contacts app. With Outlook for Android, users can utilize either the native Contacts app or Outlook for managing contact data, as contact changes are synchronized bi-directionally.

Note

In order to manage contacts (add/edit/delete) in Outlook for Android, contact sync must be enabled. This is because Outlook for Android delegates CRUD operations to the native Contacts app.

What Is Outlook

Administrators have additional capabilities with respect to contact synchronization between Outlook and the native Contacts app:

• Administrators can disable contact synchronization via an Intune App Protection Policy. For more information, see iOS app protection policy settings and Android app protection policy settings in Microsoft Intune.
• Administrators can enable contact synchronization by default on enrolled devices. For more information, see Deploying Outlook for iOS and Android app configuration settings.
• Administrators can reduce the amount of data that is exported to the native Contacts app via an Intune App Protection Policy with contact field export controls. For more information, see Deploying Outlook for iOS and Android app configuration settings.

Q: Is Outlook for iOS and Android available in China?

Yes, Outlook for iOS is available in Apple's App Store in China.

The Google Play Store is not available in China. However, Microsoft has distributed the Outlook for Android app in the following third-party app stores that are available in China:

As Google's notification service, Firebase Cloud Messaging, is not available in China, new mail push notifications do not function. Instead, Outlook for Android relies on polling notifications. For the native Microsoft sync technology, background polling occurs every 15 minutes while the app is in the background (assuming background synchronization is not disabled).

Native Microsoft sync technology migration

The following questions are about the migration from the REST API data sync protocol to the native Microsoft sync technology used by Outlook for iOS and Android for accessing mailbox data.

Q: Is there a minimum version of Outlook for iOS and Android required to use the native Microsoft sync technology?

For Outlook for iOS, users should install 3.10.1 or later. For Outlook for Android, users should install 3.0.14 or later. As always, we recommend users keep the Outlook app up to date.

Q: What will my users experience when our tenant is migrated to the native Microsoft sync technology?

Assuming the user is running a supported version of Outlook for iOS and Android, after your tenant is migrated, your users may see a brief notice indicating that we are updating their email and calendar data. Otherwise the user experience to migrate to the updated architecture will be seamless.

Q: As a tenant administrator, can I control which of my users will be migrated to the native Microsoft sync technology?

No, the migration to the native Microsoft sync technology will be on a tenant-by-tenant basis and not a per-user basis. While the tenant selection order for migration is random, we are being deliberate about migrating Microsoft 365 or Office 365 mailboxes first before we migrate on-premises mailbox accounts. If you are a customer operating in a hybrid configuration where a portion of your mailboxes remain on-premises, the on-premises users leveraging hybrid modern authentication will be migrated to the native Microsoft sync technology at a later date. This means that your Microsoft 365 and Office 365 users will migrate to the native Microsoft sync technology, while the on-premises users continue to use the REST API to connect to Exchange Online.

Once your tenant is migrated, a user will not switch to the native Microsoft sync technology, until after they launch/resume Outlook for iOS and Android.

Q: If my user doesn't upgrade to a supported build of Outlook for iOS and Android prior to my tenant's migration, does that mean the user will lose access to email and calendar data while mobile?

No, the user will continue to connect using the existing REST-based data sync protocol.

Q: Will my Intune App Protection Policies or Azure AD Conditional Access policies be affected by this migration?

No, both Intune App Protection Policies and Azure AD Conditional Access policies will continue to be applied to the targeted identity, regardless of the data sync protocol leveraged by Outlook for iOS and Android.

Q: Will I have to update my Exchange mobile device access policies (allow block quarantine (ABQ) rules)?

No, the user agent string that Outlook for iOS and Android uses does not change. For more information on what that user agent is, see Securing Outlook for iOS and Android in Exchange Online.

Q: As an Exchange administrator, is there a way for me to determine which data sync protocol Outlook for iOS and Android clients are utilizing in the Microsoft 365- or Office 365-based architecture?

Yes, execute the following command from Exchange Online PowerShell:

The ClientType property indicates which data sync protocol is in use. If the value is REST, then the client is utilizing the REST API. If the value is Outlook, then the client is using the native Microsoft sync technology.

Alternatively, a user can login to Outlook on the web and, from within Options, select Mobile Devices to view the details of a mobile device. Like the cmdlet, the user can see the value for the ClientType property.

Administrating and monitoring Outlook for iOS and Android in your organization

The following questions are about managing and monitoring the Outlook for iOS and Android app within your organization after the app has been deployed.

Q: Is it necessary to file an in-app support ticket when I experience an issue with Outlook for iOS and Android?

Yes, if you want to troubleshoot and resolve the issue, or if you want to inform us of a product defect or limitation, you will need to file an in-app support ticket. Only through filing an in-app support ticket can the Outlook app's logs get collected and analyzed by our product engineers.

Customers with a Microsoft Premier agreement can open support cases with Customer Service & Support (CSS). Instead of having the user initiate an in-app support ticket, the user can leverage Collect Diagnostics to upload the logs and share the incident ID with CSS/Premier. Collect Diagnostics will capture data from Outlook for iOS and Android, Authenticator, and the Company Portal and upload all the relevant logs to Microsoft. Microsoft Support Escalation Engineers can use the incident ID to access the diagnostic logs and troubleshoot the user's issue.

To gather the logs:

1. Within Outlook for iOS and Android's settings, tap Help & Feedback.

2. Tap Collect Diagnostics.

3. Tap Get Started.

4. Tap Upload Outlook Logs (iOS) or Collect Logs (Android).

5. Share the incident ID with CSS.

Q: As an Exchange administrator, I would like to deploy Outlook for iOS and Android, but in my testing I can't log in. What might be the issue?

Assuming authentication is not the issue, there are two areas you can check:

What Is Outlook Microsoft

1. Check whether you have an EWS application policy that restricts which client applications can connect.

2. Check whether you have EWS enabled for the account.

For more information, see Securing Outlook for iOS and Android in Exchange Online. If one of the above checks doesn't resolve the issue, please open an in-app support ticket.

Q: Will Outlook for iOS and Android support third-party unified endpoint management (MDM, EMM, or UEM) solutions?

For more information, please see Managing Outlook for iOS and Android in Exchange Online.

Q: Is a license required to use Outlook for iOS and Android?

Outlook for iOS and Android is free for consumer usage from the iOS App store and from Google Play. However, commercial users require an Office 365 or Microsoft 365 subscription that includes the Office desktop applications: Microsoft 365 Apps for Business, Microsoft 365 Business Standard, Microsoft 365 Apps for enterprise, Office 365 Enterprise E3, Office 365 Enterprise E5, or the corresponding versions of those plans for Government or Education. Commercial users with the following subscriptions are allowed to use the Outlook mobile app on devices with integrated screens 10.1' diagonally or less: Office 365 Enterprise E1, Office 365 F1, Office 365 A1, Microsoft 365 Business Basic, and if you only have an Exchange Online license (without Office). If you only have an Exchange on-premises (Exchange Server) license, you are not licensed to use the app.

Common questions from end-users

The following questions concern end-users in your organization who are using Outlook for iOS and Android on their devices to access their Exchange mailboxes.

Q: My users enabled the 'Save Contacts' advanced settings option. However, they are complaining that not all contacts have synchronized on their iOS devices. Are there limitations with synchronization?

The initial export of contacts can only begin when Outlook is in the foreground. A user can switch between apps and the export will continue while Outlook is active in memory. There are iOS limitations when syncing with iCloud that may result in data inconsistency, but Outlook will automatically trigger a reconciliation to ensure that the contacts are always consistently exported (e.g., reconciliation will remove duplicates in the event that Outlook detects exported contacts from a previous export activity). Reasons for missing/duplicate contacts might include:

• Outlook for iOS being suspended during sync.
• Enabling 'Save Contacts' simultaneously on multiple devices (such as an iPad and an iPhone).
• Accrued sync errors over time.

In the event you are seeing an inconsistency and it has not been resolved after a short period of time, wait twenty four hours and then restart the app to trigger the reconciliation process. If that does not work, perform the following steps:

1. Disable 'Save Contacts' for the affected account.
2. Check that all instances of the contacts are removed from the native iOS contacts app. If duplicates remain, go to Settings > Help & Feedback > Delete All Saved Contacts in order to remove any lingering duplicates.
3. Re-enable 'Save Contacts' for the affected account.
4. Follow the on-screen prompts, which may instruct you to keep the phone open and plugged in during initial sync.

Q: Why are the Office mobile apps required to be installed on Android in order to render attachments in Outlook, while iOS devices provide a preview of the attachments within Outlook?

This is due to the differences in the base operating systems. iOS provides native content rendering for known attachment types, which Outlook for iOS uses to provide basic attachment rendering. Android provides nothing similar. Android users have to install the Office apps and/or third-party apps in order to render attachment content.

Q: A new message included an attachment, but while I was offline I couldn't open the attachment. Why is that?

Outlook (like other mobile clients) does not download attachments automatically. This is by design, in order to conserve device space. Attachments are only downloaded at the request of the user.

Q: A week ago I accessed an attachment in a message, but now that I'm offline I can no longer access that attachment on my iOS device. However, I can access it on my Android device. Why is that?

Outlook for iOS stores attachments in our own database. As a result, every attachment we download to the client takes up a considerable amount of space in our database. To ensure the client is able to provide fast performance and take a small amount of space, we purge data rather aggressively based on usage (attachments will be cached up to seven days).

Unlike iOS, Android uses an accessible file system, so when Outlook for Android downloads an attachment, it doesn't go into the database, rather it is stored as a temporary file.

Q: Why does data within Outlook for iOS disappear and then re-appear after I toggle the Focused Inbox or the Organize by Thread settings?

Whenever those options are changed, Outlook for iOS performs a soft reset. This wipes the existing data that has been downloaded to the app and requires a re-synchronization.

Q: Can I view organization chart information in Outlook for iOS?

Yes. Outlook for iOS provides your company's organization information as part of a person's contact card details. Your company's reporting structure and a list of colleagues is also provided, to help employees connect with the people and teams they need to work with.

The list of people displayed as part of the Other Colleagues list under Show Organization is based on common email distribution lists, group memberships, and degrees of separation in the Organization structure defined in Azure Active Directory.

If you do not have organization chart data exposed in the app, consult with your directory administrator. There are two main scenarios to consider:

1. Your company has a hybrid topology where an on-premises directory is synchronized with Azure Active Directory. You will need to update Active Directory with the organization chart information, either directly in the directory or via your Human Resources system. Data will be synchronized into AAD automatically and will be accessible via the Global Address List in Exchange Online.

2. Your company only leverages Azure Active Directory for directory management. You will need to update Azure Active Directory with the organization chart information, either directly in the directory or via your Human Resources system. This data will be accessible via the Global Address List in Exchange Online.

Q: How much of my mailbox data is synchronized with Outlook for iOS and Android?

For initial folder synchronization, Outlook for iOS and Android synchronizes 500 items per folder, with up to 1000 items per folder if the user taps Load more conversations. The app periodically trims the items per folder down to the default number, in order to ensure optimal app performance.

Q: Why are tasks and notes not available with Outlook for iOS and Android?

Microsoft's strategic direction for task management and note taking on mobile devices is the To-Do and OneNote apps, respectively. OneNote provides access to notes stored in an Exchange Online mailbox with Sticky Notes. To-Do provides integration with the tasks stored in Exchange Online mailboxes; however, Outlook for iOS and Android provides users the ability to create tasks from messages and exposes top tasks in the Zero Query search pane.

Q: Does Outlook for iOS and Android support moderator message approval or rejection scenarios?

No, Outlook for iOS and Android does not support moderated message requests for approving or rejecting email. Outlook for iOS and Android does not provide an approve/reject button, so a moderator cannot approve or reject moderated messages when using Outlook for iOS and Android.