Wietse: > smtp_header_checks has a replace option. Marco: > The issue I have is that smtp_header_checks is unable to distinguish > between mail sent to intranet destinations (the VMsrunning the services) > and the Internet.
Yes, it can: /etc/postfix/transport: example.com intranet: .example.com intranet: localhost intranet: /etc/postfix/master.cf: intranet unix - - n - - smtp smtp unix - - n - - smtp -o smtp_header_checks=whatever This assumes "default_transport = smtp" which is the default. Wietse