Key Dates

Upcoming Microsoft 365 rollout milestones, feature retirements, and compliance windows — organized by Modern Work practice area. Not everything here requires action; use the Applies to note to decide if it's relevant to your environment.

Last updated: 2026-10-27 · ← Back to homepage

Security & Compliance

1 key date

Jan 1, 2027

Deadline

Purview DLP: Restrict Copilot Processing of External Emails GA

Applies to Orgs with HIPAA/GDPR obligations around email data handled by Copilot

Begin policy design for restricting Copilot's processing of external emails ahead of the January 2027 GA, particularly if your organization handles regulated data via email.

Watching

Confirmed direction, no date yet — flagged for tracking, not the calendar

Watching · since Jul 2026

OWA Light Retirement in Exchange Server

Applies to Exchange Server (on-premises) customers with users still on OWA Light

Audit for users, browser policies, or helpdesk documentation pointing to the light client (`?layout=light`) and redirect them to standard Outlook on the web. Update internal training/help desk scripts now — no fallback exists once Microsoft disables it.

Microsoft has confirmed the retirement direction but has not published a specific date yet.