Forrester says Microsoft services supporting Outlook, Teams and many others went offline around 1 p.m. ET and were starting to resume early Friday morning ET after a nearly 18-hour outage. The analyst firm says the disruption hit nearly every Microsoft service, from Outlook to Copilot to security tools such as Defender.
According to Forrester, patches and rollbacks did not immediately work because returning servers were overwhelmed by a traffic backlog, and Microsoft had to shed load and throttle downstream traffic, which likely explains partial availability in some regions.
Forrester advises customers to file SLA claims quickly. Microsoft does not apply credits automatically, and claims must be submitted within one month after the end of the outage month through M365 billing support, or through the partner for services bought via cloud solution providers. Credits cover only the affected service and are prorated when it was bundled with unaffected ones.
The firm also recommends halting mass password-reset advisories during identity outages to avoid MFA loops, reducing reliance on email-delivered one-time passwords in favor of passkeys, and using contract renewals to reassess vendor concentration.
