Use the :contains or :is match-type to determine if a text string can be matched against content in a message. Strings are enclosed in quotes when passed as arguments with the :memberof and :is match-type tags.

Policy Script Example:
if header :contains "Buy Now!" {
    pmx_quarantine "SPAM";

In this example, the match-type :contains takes a text string as an argument. If the string “Buy Now!” is matched with content in any message header, the message is quarantined with the reason “SPAM”. The stop command ends filter execution.