* Austin Witmer: > It is my understanding that header checks are processed line by line
If you want to enforce rules based on a combination of message headers, you should use a milter which can operate at the beginning of the SMTP DATA phase. At that time, all headers are available. I can recommend milter-regex (http://benzedrine.ch/milter-regex.html), a very flexible milter based on regular expressions, for implementing efficient multi-header checks. -Ralph
