MC1164375 - Retirement of "When Sending a Message" Group Policy in Classic Outlook for Windows

We’re retiring the When Sending a Message Group Policy in Classic Outlook for Windows to improve administrative flexibility and respond to customer feedback. This legacy policy grouped several mail-sending behaviors under one setting. Moving forward, these behaviors will be managed through individual policies, allowing for more granular control and easier configuration.

When this will happen:

• New individual Group Policies will be introduced starting October 14, 2025.
• The legacy When Sending a Message policy will be removed on January 13, 2026.

• Who is affected: Admins managing Classic Outlook for Windows using Group Policy.
• What will happen:
  • New individual Group Policies will be added to the Office admin templates (ADMX/ADML).
  • These policies will coexist with the legacy policy until January 2026.
  • After January 13, 2026, the legacy When Sending a Message policy will be removed.
  • Admins will need to configure the new policies individually.
  • No changes will occur automatically; migration is required.

• Review your current use of the When Sending a Message Group Policy.
• Plan to migrate to the new individual policies before January 13, 2026.
• Download the updated Administrative Template files (ADMX/ADML) from the Microsoft Download Center.
• Update internal documentation and helpdesk guidance to reflect the new policy structure.
• Learn more: Outlook for “When Sending a Message” Policy

No compliance considerations identified, review as appropriate for your organization.