During the processing of the emails Amavis-new conducts a series of tests, including so called bad-header checks which usually give a headache to system engineers because of false detections (most commonly a missing required header field or 8-bit encoding, etc)Since version 2.4.4 of Amavis-new, you can actually tweak the bad-header tests instead of turning them completely off.There is an $allowed_header_tests variable by which you can define what should be looked up during the bad-header checks, and the list is as follows:
other catchall for everything else - normally not used
mime Bad MIME (sub)headers or bad MIME structure
8bit Invalid non-encoded 8-bit characters in header
control Invalid control characters in header (CR or NUL)
empty Folded header field made up entirely of whitespace
long Header line longer than RFC 2822 limit of 998 characters
syntax Header field syntax error missing Missing required header field
multiple Duplicate or multiple occurrence of a header field
So, the final solution is to insert the aprropriate lines in the /etc/amavisd/amavisd.conf file, globally or in the appropriate block setup. For example:
$allowed_header_tests{'8bit'} = 0;
$allowed_header_tests{'missing'} = 0;
…would exclude missig items (the infamouse Date missing) and 8bit tests form the header check process.
