Users' email messages sent to Microsoft Teams channels may have been incorrectly formatted

Title: Users' email messages sent to Microsoft Teams channels may have been incorrectly formatted User impact: Users' email messages sent to Microsoft Teams channels may have been incorrectly formatted. More info: Specifically, line breaks in affected email messages may have been missing when sent to Microsoft Teams channel email addresses, causing the messages to appear as a single block of text within the channel. This issue affected plain text messages; HTML-formatted messages weren't affected. Final status: We've determined that a recent build deployment introduced a code regression affecting how plain-text email formatting was processed, resulting in line breaks not rendering as expected within Microsoft Teams channel messages. We've reverted the change and confirmed following a period of monitoring service health telemetry, that service functionality has been restored. In addition, we've received confirmation from your representatives that impact has been remediated and newly processed email messages are displaying correctly. Scope of impact: Some users sending plain text email messages to Microsoft Teams channel email addresses may have been impacted. Start time: Monday, July 20, 2026, at 2:23 PM UTC End time: Tuesday, July 28, 2026, at 7:13 AM UTC Root cause: A recent build deployment introduced a code regression that created a compatibility issue in how plain-text email content was processed, resulting in line breaks not rendering as expected within Microsoft Teams channel messages. Next steps: - We're reviewing our change testing and validation procedures to help identify similar code regressions earlier and prevent similar issues in the future. This is the final update for the event.

Title: Users' email messages sent to Microsoft Teams channels may not be formatted correctly User impact: Users' email messages sent to Microsoft Teams channels may not be formatted correctly. More info: Specifically, line breaks in the email messages may be missing when sent to Microsoft Teams channel email addresses, displaying as a single block of text in the channel. This issue affects plain text messages; HTML-formatted messages aren't affected. Current status: We're awaiting confirmation from a sample of affected users that reverting the aforementioned update successfully resolved the issue. New email messages sent to Microsoft Teams channels are expected to display correctly following the revert; however, messages processed before the revert aren't expected to be corrected retrospectively. Scope of impact: Some users sending plain text email messages to Microsoft Teams channel email addresses may be impacted. Next update by: Wednesday, July 29, 2026, at 9:00 AM UTC

Title: Users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting User impact: Users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting. More info: Specifically, the line breaks are formatted correctly when the email is composed, but when it sends to the Microsoft Teams channel email address, the formatting is incorrect and not upheld. Current status: We've completed the rollback of the update that we suspected was causing impact; however, after initial testing with a subset of affected users, it's been reported that impact still persists. We're working further with the subset of users to validate the latest test results to help inform our next troubleshooting steps. Scope of impact: Some users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting. This section may be updated as our investigation continues. Next update by: Tuesday, July 28, 2026, at 9:00 AM UTC

Title: Users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting User impact: Users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting. More info: Specifically, the line breaks are formatted correctly when the email is composed but when it sends to the Microsoft Teams channel email address the formatting is incorrect and not upheld. Current status: We're in the process of rolling back the build we believe may be responsible for this issue to determine if this allows line breaks to display correctly in email messages sent to Microsoft Teams channels. Scope of impact: Some users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting. This section may be updated as our investigation continues. Next update by: Tuesday, July 28, 2026, at 5:30 AM UTC

Title: Users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting User impact: Users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting. More info: Specifically, the line breaks are formatted correctly when the email is composed but when it sends to the Microsoft Teams channel email address the formatting is incorrect and not upheld. Current status: We're analyzing a sample email message in order to identify why line break characters are not displaying correctly when the message is sent to a Microsoft Teams channel. We've identified a recent build deployment that we believe may be responsible for the issue and are rolling it back in an effort to alleviate impact and validate our root cause theory. Scope of impact: Some users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting. This section may be updated as our investigation continues. Next update by: Tuesday, July 28, 2026, at 3:00 AM UTC

Title: Users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting User impact: Users' email messages sent to Microsoft Teams channel email addresses may not display the correct formatting. More info: Specifically, the line breaks are formatted correctly when the email is composed but when it sends to the Microsoft Teams channel email address the formatting is incorrect and not upheld. Current status: We're investigating a potential issue with incorrect line breaks in Microsoft Teams and are checking for impact to your organization. We'll provide an update within 30 minutes.