Yello incident

[Yello Enterprise] Delayed emails to Microsoft users

Yello experienced a notice incident on January 27, 2026 affecting Yello Enterprise Production - US and Yello Enterprise Production - EU and 1 more component, lasting 16h 35m. The incident has been resolved; the full update timeline is below.

Started: Jan 27, 2026, 11:07 PM UTC
Resolved: Jan 28, 2026, 03:42 PM UTC
Duration: 16h 35m
Detected by Pingoru: Jan 27, 2026, 11:07 PM UTC

Affected components

Yello Enterprise Production - USYello Enterprise Production - EUYello Enterprise UAT

Update timeline

investigating Jan 27, 2026, 11:07 PM UTC

We are aware of an issue with delayed emails to Microsoft addresses due to rate limiting from their spam protection system. We are investigating and actively working with Microsoft to resolve the issue.
resolved Jan 28, 2026, 04:42 PM UTC

Our monitoring indicates this throttling has stopped and that the deferred emails have now been delivered.