# more Received: forgery variants # same as RCVD_FORGED_WROTE but allowing capitalized host names # header RCVD_FORGED_WROTE2 Received =~ /from [0-9.]+ \(HELO \S+[A-Za-z]+\) by (\S+) with esmtp \(\S+\s\S+\) id \S{6}-\S{6}-\S\S for \S+@\1;/s header RCVD_FORGED_WROTE3 Received =~ /from \[[0-9.]+\] \(port=\d+ helo=\S+[A-Za-z]+\) by (\S+) with asmtp id \S{6}-\S{6}-\S\S for \S+@\1;/s # Another variant a bit like Sendmail instead of Exim... # header RCVD_FORGED_WROTE4 Received =~ /from [0-9.]+ \(HELO \S+[A-Za-z]+\) by (\S+) with \(8[0-9.]+\/8[0-9.]+\) ESMTP [0-9a-z]{14} for \S+@\1;/s