Most likely, not all hops in your SMTP/LMTP path support 8BITMIME, and therefor 8-bit content must be re-encoded as 7-bit (with Q-P or base64), which breaks DKIM.
Take a look at disable_mime_output_conversion in postconf(5) and Postfix FILTER_README to avoid this.
(Caveat: we're using our own MTA, not Zimbra's postfix+amavis, so I have no experience with Zimbra-specific details here)
Take a look at disable_mime_output_conversion in postconf(5) and Postfix FILTER_README to avoid this.
(Caveat: we're using our own MTA, not Zimbra's postfix+amavis, so I have no experience with Zimbra-specific details here)
Statistics: Posted by ghen — Sat Mar 08, 2025 5:58 pm
