Why are my emails showing “on behalf of” in EmailMerge365?

EmailMerge365 supports both Send As and Send on Behalf delegation models in Microsoft 365.

The behavior depends on the permission assigned to the user in the Microsoft 365 Admin Center / Exchange Admin Center, and the application automatically handles both scenarios correctly.

Settings users need to change in Admin Center

If given Send on Behalf permission

Grant the user/delegate access under:

Mailbox Delegation → Send on Behalf

Result:

If given Send As permission

Grant the user/delegate access under:

Mailbox Delegation → Send As

EmailMerge365 automatically detects and works with whichever permission model is configured by the administrator.

Article ID: 407, Created: 5/19/2026 at 8:07 PM, Modified: 5/19/2026 at 8:07 PM