i log some of the messages passing by Postfix-based relay using always_bcc = email@example.com in main.cf.
Sometimes – to track spam or problems – i need to check content of the attachments.
this comes handy
munpack -f 1483066mailfile.server
if content is embedded inline i have to edit the file and replace or just add the 2nd part if it’s not present:
Content-Disposition: attachment; filename="uniquename"