Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may have been unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may have received the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a way to circumvent impact, admins could add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Final status: We've confirmed that the fix has completed release to all environments and confirmed that this issue has been remediated using service telemetry. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may have been impacted. This information may have been updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC End time: Tuesday, April 14, 2026, at 9:00 PM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next steps: - We're continuing our analysis of the impacting configuration change to better identify and prevent similar issues in the future. This is the final update for the event.

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a way to circumvent impact, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: The fix has deployed to over 85 percent of affected infrastructure and we're monitoring as the remaining machines receive the fix. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Estimated time to resolve: We expect the fix to complete deployment, mitigating impact by Tuesday, April 14, 2026. Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Tuesday, April 14, 2026, at 10:30 PM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a way to circumvent impact, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: We're continuing to monitor the deployments of the fixes intended to repair the cmdlets responsible for the remainder of the error volume to ensure they're progressing as expected. Our current anticipated date of completion remains April 14, 2026. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Tuesday, April 7, 2026, at 11:00 PM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a way to circumvent impact, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: We've completed deploying fixes for cmdlets responsible for seven percent of our current total error volume. For the remaining error volume, we've initiated deployments of our fixes for those cmdlets responsible, and anticipate it may take three weeks for these deployments to complete. We'll be monitoring their progress and providing updates as these deployments continue, with a current target date of April 14, 2026, for completion and impact resolution. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Tuesday, March 31, 2026, at 11:00 PM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a way to circumvent impact, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: Development and validation of the necessary additional fixes to address the remaining impacted cmdlets is ongoing, and we're assessing the progress to help calculate an estimated timeline for remediation. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Tuesday, March 24, 2026, at 11:00 PM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a workaround, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: We've confirmed the first fix has completed deployment, and we've received reports from a subset of affected users that some cmdlets have been succeeding as a result. We're continuing to develop and validate additional fixes to address the remaining impacted cmdlets, and we'll confirm a timeline for full remediation as one becomes available. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Monday, March 23, 2026, at 11:00 PM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a workaround, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: We've completed the validation of our initial fix which is expected to resolve cmdlets that account for approximately seven percent of the total identified failures. Fixes for additional cmdlets are in various states of development and validation. We'll provide a complete remediation timeline once one is available. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Friday, March 20, 2026, at 11:30 PM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a workaround, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: We've identified that each of the 64 affected cmdlets requires its own fix to correct this issue completely. The current batch of code fixes focuses on the most used and reported cmdlets that are impact by this event. The development and validation of this batch of potential code fixes for a subset of the affected PowerShell cmdlets is ongoing. Our work to exempt identified affected organizations from cross-location mailbox placement moves is ongoing, and we’re working to ensure all affected organizations are exempted. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Tuesday, March 17, 2026, at 11:00 PM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a workaround, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: Our work to exempt identified affected organizations from cross-location mailbox placement moves is ongoing, and we’re working to ensure all affected organizations are exempted. Simultaneously, we're beginning development and testing of two potential code fixes for a subset of the affected PowerShell cmdlets, and we aim to provide a timeline to deployment once one becomes available. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Tuesday, March 10, 2026, at 11:00 PM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a workaround, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: We're continuing to exempt identified affected organizations from cross-location mailbox placement moves to help alleviate impact. We've implemented a code fix that has restored the functionality of the Set-Mailbox cmdlet. We're strategizing fixes for each affected PowerShell cmdlet to completely remediate impact across all affected regions. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Tuesday, March 10, 2026, at 12:00 AM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a workaround, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: Our efforts to exempt identified affected organizations from cross-location mailbox placement moves is progressing, and we're continuing to validate a long term solution to fully remediate the impact across all affected regions. We anticipate a timeline for resolution will be available at the time of our next update. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Thursday, March 5, 2026, at 12:00 AM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a workaround, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: We've identified that a configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. To remediate this, we're exempting identified affected organizations from cross-location mailbox placement moves while we work to validate a long-term solution. Once available, we'll provide a resolution timeline. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Start time: Thursday, January 15, 2026, at 12:38 AM UTC Root cause: A configuration change intended to improve mailbox load balancing enabled mailbox placement across service locations within the same region, which caused certain PowerShell mailbox management cmdlets to fail when administrators attempted actions against mailboxes located outside their admin session’s service location. Next update by: Saturday, February 28, 2026, at 12:00 AM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." As a workaround, admins can add the following ConnectionUri parameter to the query string: Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell?email=" Current status: We've determined that the impact isn't limited to the Japan region, and some admins in Australia, Great Britain, Latin America, India, and Canada regions may be affected. Additionally, we've confirmed a workaround which affected admins may use to mitigate the issue as we continue our analysis of affected mailbox samples to determine the source of impact. Scope of impact: Some admins in Japan, Australia, Great Britain, Latin America, India, and Canada regions attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Next update by: Tuesday, February 24, 2026, at 9:00 PM UTC

Title: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." Current status: We've received feedback that reverting the offending change did not provide the desired resolution. We're now reviewing the latest mailbox samples to help isolate the root cause. Scope of impact: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Next update by: Monday, February 23, 2026, at 7:30 AM UTC

Title: Some admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins may be unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." Current status: We’ve reverted the suspected offending change and are reaching out to the admins who initially reported the issue to confirm resolution and validate our root cause. Scope of impact: Some admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings may be impacted. This information may be updated as our investigation continues. Next update by: Friday, February 20, 2026, at 11:30 AM UTC

Title: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." Current status: We’ve identified that a recent change may be contributing to impact. We've developed a fix which is currently being validated with one affected organization before broader deployment. In parallel, we’re continuing to investigate to fully understand the underlying cause of the issue. Scope of impact: Your organization is affected by this event, and admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings are impacted. This information may be updated as our investigation continues. Next update by: Friday, February 20, 2026, at 5:30 AM UTC

Title: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." Current status: We're continuing to review support case details and the error associated with impact so that we can better understand why the issue is occurring and identify our next troubleshooting steps. Scope of impact: Your organization is affected by this event, and admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings are impacted. This information may be updated as our investigation continues. Next update by: Thursday, February 19, 2026, at 1:30 PM UTC

Title: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. More info: Admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings receive the following error: "Can't connect to the mailbox of user Mailbox database guid: [mailbox guid] because the ExchangePrincipal object contains outdated information. The mailbox may have been moved recently." Current status: We're reviewing the support case details and the error associated with impact so that we can better understand why the issue is occurring and identify our next troubleshooting steps. Scope of impact: Your organization is affected by this event, and admins attempting to use a PowerShell cmdlet to change some users' Exchange Online mailbox settings are impacted. This information may be updated as our investigation continues. Next update by: Thursday, February 19, 2026, at 8:30 AM UTC

Title: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet User impact: Admins are unable to change some users' Exchange Online mailbox settings when using a PowerShell cmdlet. 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.