Scenario: When ‘Sending on Behalf’ to an internal recipient, the sender displays correctly/as expected:
Steven on behalf of TestService123
BUT, when “Sending on Behalf” to an external recipient, the result of the sender line displaying correctly is unpredictable. It may only show the email address of the sender you sent on behalf of and may not include your delegated email address.
TestService123 (TestService123@domain.com)
Reason: The “Send on Behalf” feature is an Exchange feature. Unless your external mail system knows how to process the headers ‘From’ and ‘Sender’ lines, it may only show it coming from the ‘From’ address, the email address you sent on behalf from and not include your delegated email address.
Ex-Shell 