Microsoft 365 Will Let Organizations Recall External Emails

Cross-tenant Message Recall will soon let Microsoft 365 organizations recall emails sent to users in trusted external tenants. Until now, Exchange Online only supported Message Recall when the sender and recipient belonged to the same Microsoft 365 tenant.

The expansion gives organizations more control over messages accidentally sent to external partners, subsidiaries, contractors, and affiliated companies.

How cross-tenant Message Recall works

The feature relies on mutual trust between Microsoft 365 organizations.

The recipient organization decides which external tenants can recall messages from its users’ mailboxes. For example, if Company A sends an email to Company B, Company B must add Company A’s tenant ID to its allow list before Company A can recall the message.

If the recipient organization has not approved the sender’s tenant, Exchange Online will reject the recall request and return an error.

This approach prevents unknown or untrusted organizations from attempting to remove messages from recipients’ mailboxes.

Cross-tenant recall remains disabled by default

Microsoft will not enable the feature automatically.

Exchange Online administrators must enable cross-tenant recall and add at least one trusted external tenant to the allow list. Without an approved tenant ID, recall requests from external Microsoft 365 organizations will fail.

Admins can enable or disable the feature with the following Exchange Online PowerShell command:

Set-CrossTenantRecallConfiguration -CrossTenantRecallEnabled $true

To disable it, admins can set the value to $false.

How to manage the trusted tenant list

Administrators can add approved Microsoft 365 tenant IDs with:

Set-CrossTenantRecallConfiguration -AllowedSenderTenantIds @{Add="tenantId 1","tenantId 2"}

They can remove tenants with:

Set-CrossTenantRecallConfiguration -AllowedSenderTenantIds @{Remove="tenantId 1","tenantId 2"}

Organizations will need to coordinate with their external partners before enabling the feature. The recipient tenant must explicitly trust the organization that may need to recall messages.

Recall will work similarly to internal messages

After administrators configure the required trust relationship, cross-tenant Message Recall will behave similarly to recall within the same Microsoft 365 organization.

Recall success will depend on the recipient organization allowing requests from the sender’s tenant.

Rollout starts in August 2026

Microsoft plans to begin rolling out cross-tenant Message Recall in mid-August 2026. The company expects to complete the rollout by mid-September 2026.

The feature will become available across worldwide Microsoft 365 environments, Government Community Cloud, GCC High, Department of Defense environments, and Microsoft 365 operated by 21Vianet.

The gradual rollout means some organizations may receive the feature before others during the August-to-September deployment period.

Microsoft is also preparing other Exchange and Outlook changes. The company plans to disable OWA Light by default in an upcoming Exchange Server update, while the new Outlook will warn users when they attempt to reply to an older message in a conversation that already contains a newer response.