In replying to email from an external (internet) mail sender, a doclink is included after the “subject” in the body of the reply, i.e. the subject of the original message.
The outbound mail is sent in HTML and plain text format.
The recipient’s mail server (that’s the original sender, now receiving the reply) is rejecting the incoming email because the HTML version of the doclink is rendered using in-line images. Not all, but a significant number of mail servers are rejecting.
I’ve had to switch off HTML mail in the server configuration to stop the bounces. Anyone else had this problem? Any way to solve the problem while leaving outbound HTML mail in the configuratin?