Some users may see unwanted add-ins appearing automatically across all Outlook clients

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're coordinating with a subset of affected users who are performing the actions needed to remediate the impact to ensure that running the command and installing previously installed apps fully resolves the issue. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in sync pipeline isn't processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact. Next update by: Friday, September 4, 2026, at 6:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're coordinating with a subset of affected users who are performing the actions needed to remediate the impact to ensure that running the command and installing previously installed apps fully resolves the issue. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in sync pipeline isn't processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact. Next update by: Friday, September 4, 2026, at 6:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: The fix deployment has completed. We've determined that this fix is viable for all affected users but to see the impact remediated, users will need to run the following command: "Set-App -Identity "" -DefaultStateForUser Disabled -OrganizationApp -PrivateCatalog". After running this command all users who previously installed add-ins may need to install them again. We're providing time for affected users to run this command and remediate impact before we consider this resolved. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in sync pipeline isn't processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact. Next update by: Tuesday, September 1, 2026, at 6:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: Our fix deployment timeline reports that our solution will require a bit longer than previously expected. In parallel, we've determined that the deployment will not be viable for all affected users, and that additional mitigation efforts will be required. We're further analyzing our potential long-term solutions for remediating the impact. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in sync pipeline isn't processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact. Next update by: Wednesday, August 26, 2026, at 6:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: Based on the rate of the deployment progression, we now anticipate the fix will be available on August 22, 2026. We're continuing to monitor as the process nears completion and will begin reaching out to a subset of affected users once the fix is fully saturated to begin verifying impact remediation. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in sync pipeline isn't processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact. Next update by: Monday, August 24, 2026, at 6:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We’re continuing to monitor the progress of the fix to ensure it propagates successfully. We still suspect this will complete by Wednesday, August 26, 2026, and we’ll provide further updates as they become available. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in sync pipeline isn't processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact. Next update by: Wednesday, August 19, 2026, at 6:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We’ve developed and begun deploying the fix to the affected environments. We’re monitoring its progress to ensure it propagates successfully, and based on our current estimates, we expect deployment to complete by Wednesday, August 26, 2026. We’ll provide further resolution updates as they become available. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in sync pipeline isn't processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact. Next update by: Wednesday, August 12, 2026, at 6:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're developing a fix aimed at correcting the affected portion of Exchange Online add-in sync pipeline that’s resulting in impact, and we’ll provide a timeline for its validation and deployment as one becomes available. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in sync pipeline isn't processing add-in state information as expected. This is causing incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available, which is resulting in impact. Next update by: Tuesday, August 11, 2026, at 6:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We've identified that a portion of the Exchange Online add-in synchronization pipeline isn't processing add-in state information as expected, resulting in incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available. We're continuing to validate with a subset of affected users whether removing and re-adding an add-in or deploying a test add-in to force synchronization can serve as a viable workaround while our investigation into the underlying cause continues in effort to isolate the source of the issue and identify an appropriate remediation action. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Start time: Friday, July 17, 2026, at 10:26 AM UTC Root cause: A portion of the Exchange Online add-in synchronization pipeline isn't processing add-in state information as expected, resulting in incorrect EnabledStatus values being returned and Outlook automatically displaying add-ins configured as Available. Next update by: Monday, August 10, 2026, at 6:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're continuing to validate with a subset of affected users whether removing and re-adding an add-in or deploying a test add-in to force sync can serve as a viable workaround while the root cause investigation remains ongoing. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Thursday, August 6, 2026, at 5:30 PM UTC

Title: Users see unwanted add-ins appearing automatically across all Outlook clients User impact: Users see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We successfully reproduced the issue internally and found that triggering an add-in sync caused the unwanted add-ins to disappear. We are currently validating, with a subset of affected users, whether removing and re-adding an add-in or deploying a test add-in to force sync can serve as a viable workaround while the root cause investigation remains ongoing. Scope of impact: Your organization is affected by this event, and all users see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Wednesday, August 5, 2026, at 9:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're continuing our efforts to reproduce impact within our internal testing environment while reviewing HAR logs alongside any recent updates that may be causing or contributing to impact, to isolate this issue's underlying cause. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Tuesday, August 4, 2026, at 9:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We received feedback from a subset of affected users that the potential temporary remediation was insufficient. We're continuing to review provided HAR logs while we reproduce the impact using our internal testing tenant to gain further understanding of the issue. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Monday, August 3, 2026, at 7:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We've identified a potential temporary remediation while we work towards long-term resolution. We're reaching out to validate this temporary remediation with a portion of the impacted users to determine if it will be an effective solution. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Friday, July 31, 2026, at 7:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're reviewing newly collected HAR logs provided by a subset of affected users to aid us in our root cause investigation. In the meantime, we're developing a short term mitigation plan to provide relief while our investigation is ongoing. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Thursday, July 30, 2026, at 11:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: Our investigation of the conflicting add-in configurations is ongoing, and we're reaching out to your representatives for additional contextual data and fresh HTTP Archive (HAR) files collected from both Outlook desktop and Outlook on the web clients for further analysis. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Thursday, July 30, 2026, at 7:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're continuing to analyze conflicting add-in configurations which may be contributing to impact along with our continued analysis of relevant recent changes to the affected configurations to isolate the underlying source of impact. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Wednesday, July 29, 2026, at 9:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We've identified conflicting add-in configurations which may be contributing to impact. We're expanding our investigation into recent relevant changes to the configurations to confirm the root cause. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Wednesday, July 29, 2026, at 7:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're analyzing the properties being utilized to display add-ins for an affected user along with our continued analysis of the HAR file to isolate potential sources of impact. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Tuesday, July 28, 2026, at 10:00 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're analyzing HTTP Archive format (HAR) traces provided by your representatives and reviewing support cases to further our understanding of the current impact scenario and to assist with determining our next troubleshooting steps. Scope of impact: Impact may occur for some users that may see unwanted add-ins appearing automatically across all Outlook clients. This section may be updated as the investigation progresses. Next update by: Tuesday, July 28, 2026, at 4:30 PM UTC

Title: Some users may see unwanted add-ins appearing automatically across all Outlook clients User impact: Users may see unwanted add-ins appearing automatically across all Outlook clients. More info: These add-ins are configured to be available to users by admins but aren’t expected to be automatically installed. Current status: We're investigating a potential issue with Exchange Online and checking for impact to your organization. We'll provide an update within 30 minutes.