Copilot rewrite fails in classic Outlook for some users
Reviewed by Helen Jones
NHSmail Support posted Microsoft reference CP1387482 for a Microsoft 365 Copilot service degradation affecting the rewrite feature in classic Outlook. Affected users who select text and use Copilot rewrite may see a "Sorry, something went wrong" error. The same feature is reported as working in Outlook on the web and new Outlook. The issue was still listed as ongoing in the 15 June 2026 update while Microsoft collected logs and reproductions from affected users.
Before this incident, classic Outlook could feel like the safe, familiar place to keep email habits stable while Copilot features arrived around it. If rewrite worked once, it was easy to build it into daily triage without thinking about the client underneath. The degradation shows that Copilot-assisted email work can now fail by client, not only by user licence or prompt quality. Productivity workers need a fallback for rewriting important replies so one broken AI button does not derail the whole inbox routine.
Analysis
If Copilot rewrite is part of your email routine, test the same message in Outlook on the web or new Outlook before reworking the whole draft manually. Keep a two-line manual rewrite checklist for days when Copilot features are degraded.
Source note
Pulse published by Collab365 Spaces, reviewed by Helen Jones on . Cite as "Copilot rewrite fails in classic Outlook for some users", Collab365 Spaces. 1 source referenced.