Fasthosts incident
Sending email to Microsoft-hosted email addresses may not be possible
Fasthosts experienced a major incident on June 30, 2026 affecting Sending Mail, lasting 6d 1h. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- identified Jun 30, 2026, 10:51 AM UTC
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.
- identified Jun 30, 2026, 01:04 PM UTC
We have eliminated the disruption for some of those affected.
- monitoring Jun 30, 2026, 05:09 PM UTC
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.
- monitoring Jul 02, 2026, 06:41 AM UTC
We are still working on resolving this issue. Our apologies for the inconvenience caused.
- identified Jul 02, 2026, 01:43 PM UTC
We have found the cause for the disruption and are working on resolving it.
- identified Jul 03, 2026, 07:10 AM UTC
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.
- monitoring Jul 06, 2026, 10:51 AM UTC
We have eliminated the disruption for almost everyone affected.
- resolved Jul 06, 2026, 12:17 PM UTC
This incident has been resolved.