Ubivox incident
Microsoft has issues receiving email
Ubivox experienced a minor incident on September 4, 2026 affecting Email Delivery, lasting 1h 13m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- monitoring Sep 04, 2026, 12:05 PM UTC
Microsoft currently has issues receiving email. This means that many emails sent to Office365 recipients will result in a soft bounce with this message: 52.101.68.10 failed after I sent the message./Remote host said: 451 4.7.500 Server busy. Please try again later from \[REDACTED\]. (S77714) \[[**DB1PEPF000509E3.eurprd03.prod.outlook.com**](http://DB1PEPF000509E3.eurprd03.prod.outlook.com) 2026-09-04T08:16:36.825Z 08DF04AEA47F75BA\]/ If you have access to the Office365 admin page they have created an issue to follow here: We're monitoring the issue but for now there is nothing we can do to force emails through. Emails sent during Microsoft downtime will be tried again for the following 48 hours until delivery is possible. (We're mainly creating this issue to have a place to point clients to for updates. There is nothing we can do inhouse to solve the issue.)
- resolved Sep 04, 2026, 01:19 PM UTC
This incident has been resolved by Microsoft. We're have emptied all queues and delivered all waiting email.