Sending email to Microsoft-hosted email addresses may not be possible

Incident Report for Fasthosts

Resolved

This incident has been resolved.
Posted Jul 06, 2026 - 13:17 BST

Monitoring

We have eliminated the disruption for almost everyone affected.
Posted Jul 06, 2026 - 11:51 BST

Update

Microsoft has confirmed mitigations on their side, but we're still seeing blocks. These happen when Microsoft detects traffic it considers higher than expected and applies restrictions outside of our control. Our engineering team is actively working to optimise mail flows and reduce the chance of these blocks. We're in regular contact with Microsoft to push for a lasting fix, and this remains a top priority.
Posted Jul 03, 2026 - 08:10 BST

Identified

We have found the cause for the disruption and are working on resolving it.
Posted Jul 02, 2026 - 14:43 BST

Update

We are still working on resolving this issue. Our apologies for the inconvenience caused.
Posted Jul 02, 2026 - 07:41 BST

Monitoring

The affected IP address has been unblocked. Now that service has been restored and the IP address's reputation is being re-established, it may take up to 24–48 hours for the change to fully propagate across our systems. During this time, some email sending limits may still remain in effect. Thank you for your patience and understanding.
Posted Jun 30, 2026 - 18:09 BST

Update

We have eliminated the disruption for some of those affected.
Posted Jun 30, 2026 - 14:04 BST

Identified

Some emails sent to Microsoft-hosted email addresses may be rejected due to Microsoft blocking some of our IP addresses.

We are in contact with Microsoft to request de-listing.

Please accept our apologies for any inconvenience you may be experiencing.
Posted Jun 30, 2026 - 11:51 BST
This incident affected: Email (Sending Mail).