inconsistent unread email counts in Outlook for Android with a Microsoft 365 account.

Jayla Monares 0 Reputation points
2026-11-05T14:44:14.15+00:00

We're experiencing inconsistent unread email counts in Outlook for Android with a Microsoft 365 account.

Some folders contain unread emails, but their unread counts do not appear beside the folder names in the Android app.

For example, NM-015 and NM-016 each show 3 unread emails in Outlook Web, but neither displays the count in Outlook Android.

We've reproduced this issue on two Android phones. Outlook Web displays the counts correctly.

Could you confirm whether this is a known limitation or bug and whether there is a workaround or planned fix?

Outlook | Outlook for mobile | Outlook for Android | For business
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  1. Ana Le 2,960 Reputation points Independent Advisor
    2026-11-05T14:56:52.73+00:00

    Hi,

    I understand that missing folder counts make it difficult to keep track of unread messages, especially when Outlook on the web shows the correct counts.

    As the forum’s AI recommended, you can continue using Outlook on the web to check unread counts while this is investigated. I couldn’t find this exact symptom listed on Microsoft’s Outlook mobile known-issues page, so I can’t confirm whether it is a documented limitation or acknowledged bug, or provide a confirmed fix timeline.

    Before trying further troubleshooting, could you clarify:

    • When you open NM-015 and NM-016 on Android, are all three unread messages visible and still marked as unread? Does the count appear after refreshing the folder and returning to the folder list?
    • Are these folders in your own mailbox or a shared mailbox? What Outlook app and Android versions are installed on both phones?

    Please try the Outlook update suggested in the AI response if you haven’t already, then fully close and reopen the app. If the issue persists, an additional step to try before removing and re-adding the account is Outlook Settings > select the affected email account > Reset Account. Try this on one phone first, allow synchronization to complete, then check the folders again. Microsoft recommends this for incomplete or incorrect app data: Reset or refresh Outlook mobile.

    The AI response also mentions the 500–1,000-item synchronization limit. Although Microsoft documents that limit, it does not establish that this limit causes missing folder unread counts. I would not attribute your issue to it based on the information available.

    If the counts remain missing, please follow the AI’s recommendation to have your Microsoft 365 administrator open a support request through Microsoft 365 admin center > Help & support. Include screenshots comparing the same folders, the app and Android versions, and the results from both phones. Mask personal or sensitive information in any screenshots shared here.

    See Get support for Microsoft 365 for business. Support can investigate the discrepancy and check whether an existing issue or fix applies.

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  2. AI answer

    2026-11-05T14:45:31.2+00:00

    Microsoft has not publicly documented missing per-folder unread counts in Outlook for Android as a known limitation or active issue, and no public fix or rollout date is currently listed on the Outlook mobile known-issues page.^1^

    Because Outlook on the web shows the correct counts and the behavior occurs on two phones, continue using Outlook on the web as the reliable workaround and report the mobile-client discrepancy through Microsoft 365 support.

    Supported troubleshooting

    These actions rebuild or refresh Outlook’s local mobile state; they do not correct the mailbox data shown correctly in Outlook on the web.

    1. Update Outlook
      • Open Google Play Store → Outlook → Update.
      • Reopen Outlook and refresh NM-015 and NM-016.
    2. Clear the Android app cache
      • Open Android Settings → Apps → Outlook → Force stop.
      • Go to Storage → Clear cache.
      • Reopen Outlook and allow the affected folders to synchronize. Clearing the cache retains Outlook data.^2^
    3. Rebuild the account’s mobile synchronization state
      • In Outlook, open Settings, select the Microsoft 365 account, and remove it.
      • Add the account again and allow folder synchronization to complete.
      Microsoft recommends removing the synchronization relationship and re-adding the account when a Microsoft 365 work or school account stops synchronizing correctly.^2^
    4. Exclude Android background restrictions
      • Open Android Settings → Battery → Battery optimization → All apps.
      • Set Outlook to Not optimized.
      • If used for authentication or device management, do the same for Microsoft Authenticator and Intune Company Portal.
      Background synchronization supplies badge updates and mailbox information. Android Doze, app standby, or manufacturer-specific restrictions can prevent those updates.^3^

    Check whether folder size is a factor

    Outlook for Android initially synchronizes 500 items per folder and can load up to 1,000; it periodically trims the local set back to 500.^4^

    If the unread messages in NM-015 and NM-016 are older than the locally synchronized items:

    1. Open each folder in Outlook Android.
    2. Load additional conversations if that option appears.
    3. Check whether the unread messages and folder count then become visible.

    This limit could explain older unread items being absent locally, but it does not establish the cause if all three unread messages are recent and visible in the Android folder.

    Escalation and fix status

    If the counts remain absent after rebuilding the account:

    • Have a Microsoft 365 administrator open Microsoft 365 admin center → Support → Help & Support.
    • Include:
      • Screenshots of the same folders in Outlook on the web and Android.
      • Outlook Android version and Android OS versions.
      • Folder names and whether they are ordinary, shared-mailbox, or nested folders.
      • Approximate folder item counts and dates of the unread messages.
      • Confirmation that the issue reproduces on two phones.
    • Check Microsoft 365 admin center → Health → Service health for a tenant-specific advisory and use Report an issue if none matches.

    Microsoft’s public documentation does not currently identify this exact symptom as either intentional folder-count behavior or an acknowledged defect. Consequently, only Microsoft Support can confirm whether the tenant is affected by an unpublished service incident or product bug and provide an internal status. Microsoft’s mobile troubleshooting guidance directs Microsoft 365 business users to their administrator or technical support for unresolved synchronization issues.^2^

    References

    1. Fixes or workarounds for Outlook mobile apps | Microsoft Support
    2. Troubleshoot Outlook mobile issues | Microsoft Support
    3. Outlook for iOS and Android in Exchange Online: FAQ
    4. How much of my email does your app sync? | Microsoft Support
    AI-generated content may be incorrect. Read our transparency notes for more information.

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