Emailing Bills Error: “The recipient's address is not valid” and Other Email Issues After Windows Update (Known Issue)

We are currently seeing a known issue affecting some users when emailing bills, including errors such as:
“Failure: The recipient's address is not valid.”

The issue persists even when using both 32-bit and 64-bit versions of Outlook, which are not functioning as expected in this scenario.

After further investigation, this is not caused by Timeslips. We have identified a recent Microsoft Windows update as the likely source. Specifically, the April 2026 Windows 11 (version 25H2) update (build 26100.8247) has introduced a known issue impacting email functionality in third-party applications such as Outlook Classic, backup tools, and CRM systems. This appears to be related to a regression in the Windows networking stack and MAPI layer.

Additionally, rolling back the Windows update does not appear to reverse the impact it has already had on Microsoft Outlook functionality.

At this time, this issue is outside the scope of Timeslips support. We recommend contacting Microsoft Support for assistance or monitoring Microsoft’s official updates for a resolution. Please chck back for updates.

We will share any new information here as it is received.

D’Wan Sophia Harvey

Senior Technical Support Specialist

 Sage.com | Twitter | Instagram | Facebook | YouTube | LinkedIn | Community

     

"Success is not just about what you accomplish in your life; it’s about what you inspire others to do."

      – Anonymous

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  • Hello Everyone,

    We want to provide an update regarding the recent Outlook email functionality issue that may have impacted some Sage Timeslips users, particularly when sending emails (such as bills or statements) through Outlook.

    Current Status

    Microsoft has released an update that resolves this issue for many affected users.

    Fix Details

    • Version: 2604
    • Build: 19929.20172

    Customers with automatic updates enabled should receive the fix by simply closing and reopening Outlook.

    What Timeslips Users Should Do

    If you or your clients are still experiencing issues when sending emails from Timeslips via Outlook:

    1. Verify the installed Microsoft Office version/build
    2. Update to Version 2604 (or later)
    3. Restart Outlook before testing email functionality again in Timeslips

    If the issue persists after updating, continue standard troubleshooting and log a support case as needed.

    Important Notes

    • This issue primarily affects emails associated with multiple aliases
    • Some customers may have seen partial improvement from a previous Microsoft update
    • We are still seeing ongoing reports in certain cases

    Next Steps from Microsoft

    Microsoft has confirmed they have identified the root cause and are working on a more comprehensive fix, expected in:

    • Upcoming Version: 2605
    • Release Date: To be announced

    Additional Resources

    For more details, refer to Microsoft’s official release notes:
    learn.microsoft.com/.../current-channel

    We’re Here to Help

    Please continue to monitor for any remaining issues when sending emails from Timeslips. If problems persist after updating, escalate through the appropriate support channels so we can assist further.

    Thank you for your patience and for being part of the Sage Timeslips community.

    D’Wan Sophia Harvey

    Senior Technical Support Specialist

     Sage.com | Twitter | Instagram | Facebook | YouTube | LinkedIn | Community

         

    “Your impact on others will always outlast your achievements.”

    – Anonymous

  • in reply to Sophia Harvey

    Thanks  .

    Hey  , can you load the Microsoft update and let us know if it solves your issue?

    Nancy Duhon, Esq.
    Duhon Technology Solutions, LLC
    Master Certified Consultant for Sage Timeslips
    Providing individual Consultations and Third Party Remote Desktop Support - including older/unsupported versions.
    Co-Author of "The E-Billing Process Using Sage Timeslips©" available here: www.certifiedresourcesnetwork.com/
    LawPay Partnered Consultant
    MyCase Consultant
    404-325-9779
    [email protected]

Reply
  • in reply to Sophia Harvey

    Thanks  .

    Hey  , can you load the Microsoft update and let us know if it solves your issue?

    Nancy Duhon, Esq.
    Duhon Technology Solutions, LLC
    Master Certified Consultant for Sage Timeslips
    Providing individual Consultations and Third Party Remote Desktop Support - including older/unsupported versions.
    Co-Author of "The E-Billing Process Using Sage Timeslips©" available here: www.certifiedresourcesnetwork.com/
    LawPay Partnered Consultant
    MyCase Consultant
    404-325-9779
    [email protected]

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