What comparison operators can be used when making meta rules? For instance the following is using the && operator for testing that both tests are passed. I am assuming then that there is NOTs and ORs, but I can find no specific references to the syntax.
meta VALID_PAYPAL_EMAIL (ONLY_PAYPAL_FROM && MSGID_FROM_MTA_PAYPAL )
See man Mail::SpamAssassin::Conf. It's very well detailed in the section describing "meta".
In 2.4x and higher there are 3 operators: && - boolean and ! - boolean not || - boolean or
in 2.5x and higher there are arithmetic operators allowing you to do addition, subtraction, multiplication, greater-than, less-than, etc.
