I have access to our Office 365 / Microsoft 365 admin portal.
Some emails appear prefixed with [External] on the subject line. This prefix causes issues, and I have been asked to remove that.
How do I configure the Admin Portal to NOT prefix emails from some emails with [External]?
2 Answers
How do I configure the Admin Portal to NOT prefix emails from some emails with [External]?
You will need to remove the prepend action, for the Exchange Transport Rule, that governs emails that are received outside of your organization. You can simply remove the action that prepends text to the subject line when the email is outside of your organization.
Source: Marking External Email with an Exchange Transport Rule
1I contacted Microsoft 365 support. I attempted to locate above and only saw how I can apply rules, which I did not. I had no rules.
The short story is that an email sent from here yielded [External] XXXXX on the subject line at the recipient's inbox, not our inbox. That [External] tag caused issues at the recipient end, as it got flagged as a potential phishing email.
I thought the external tag was at our end, not their end.
The solution is that the problem is not our problem, but THEIR problem. The recipient has to have their admin add an exception for our user or our domain or simply have their admin delete the rule.
I would think that the recipient should have known that, as they had the rule set up, not me. I never heard of the external tag before today, and yet I solved their problem. Hmm.
