A user recently reported that he cannot send emails after a recent email migration.
Whenever he tries to send an email it tells him the delivery has failed or was undeliverable because of "Security Policies" and #550 5.7.1 Delivery not authorized, message refused ##
I am still attempting to gather more information from the user, especially what exact email addresses he is sending to when he gets this error.
The user also has attachments with each of the failed emails. I will find out more about this as well, as that could be related to the issue.
Apologies if I'm a little vague. Just wanted to ask if anyone has a guess.
Any help is appreciated. Thank you.