How to make a rule for filtering messages in Exim?

Question

linux

Good afternoon, we have a server with sites on joomla, wp. Sites often send spam. I wanted to write rules for Exim, which should take stop words from a file and look for them in outgoing mail. If the word is present, discard the letter.
Please tell me how to make this rule. Ran this:

deny message = Your letter contain many spam words!
logwrite = This message contains spam-word ($message_body)
condition = ${lookup{$message_body}lsearch{/etc/exim/blacklist/spam-word}}

but does not plow.