Microsoft 365 Alert – Service Degradation – Microsoft Teams – Some users’ legitimate email messages may be marked as phishing and quarantined in Exchange Online – ONGOING
09/02/2026 08:30:00 AM
NHSmail Reference: INC46744068
Microsoft Reference: EX1227432
Issue Status: ONGOING
Issue Description: Users’ legitimate email messages may be marked as phishing and quarantined in Exchange Online.
Current Update: 10/02/2026 08:39:00 AM – Microsoft discovered an issue when unblocking some legitimate URLs which they must resolve prior to releasing the quarantined messages. They are working on addressing the blocker so they can proceed with unblocking the legitimate URLs and releasing the quarantined messages to remediate.
Scope of impact: Some users attempting to send or receive Exchange Online email messages may be impacted.
Preliminary root cause: An updated URL rule intending to identify more sophisticated spam and phishing email messages is incorrectly quarantining legitimate email messages in Exchange Online, resulting in impact.
Next update by: Wednesday, February 11, 2026, at 1:00 AM UTC