I'm trying to reject mail without a valid From:-address in the mail header (other than reject_non_fqdn_sender which only affects the mail envelope). However, the following rule in header_checks seems to match valid From:-addresses instead of the opposite:
!/^From:.*<.*@.*>/ REJECT No valid sender email address in mail header Did I misunderstand the idea of the ! in front of the /pattern/? Or how could I achieve this? Thanks, Juerg
