Henk van Oers: > > Quote from header_checks (5): > "" > DUNNO Pretend that the input line did not match any pat- > tern, and inspect the next input line. This action > can be used to shorten the table search. > > For backwards compatibility reasons, Postfix also > accepts OK but it is (and always has been) treated > as DUNNO. > "" > > I was trying to use action OK to jump out of header checks. > That is: not only skip the next patterns, but also the next > input lines.
According to the above documentation, Postfix does not work that way. Whitelisting based on a single header line is unsafe. Doing a proper job requires an external content filter. Wietse