Microsoft 365 Alert – Service Degradation – Microsoft 365 suite – Some users may be blocked from opening URLs in Exchange Online messages and Microsoft Teams – RESOLVED

Announcements Sourav Nandi

08/09/2025 08:50:00 AM

NHSmail Reference: INC46622679

Microsoft Reference: MO1148487

Issue Status: RESOLVED

Issue Description: Some users may be blocked from opening URLs in Exchange Online messages and Microsoft Teams.

More info: Additionally, admins may receive alerts titled “A potentially malicious URL click was detected involving one user”; however, the URLs have been confirmed as safe.
Some email messages may have also been incorrectly quarantined.

Final Update: 11/09/2025 08:50:00 AM – After an extended period of monitoring, Microsoft have confirmed that the service remains healthy and users will no longer experience impact.

Scope of impact: Any user receiving email messages or messages within Microsoft Teams containing specific URLs may be affected.

Root cause: An anti-spam service incorrectly flagged URLs contained within other URLs as potentially malicious, resulting in impact.

Next steps: Microsoft are further reviewing why the anti-spam service incorrectly flagged the affected URLs to prevent similar issues from happening in the future.