Configure it :
SPAM_REGEX YES REGEX_FILE ze-regex REGEX_MAX_SCORE 50 SPAM_REGEX_MAX_MSG_SIZE 40000 SPAM_REGEX_MAX_MIME_SIZE 15000 DUMP_FOUND_REGEX YES REGEX_LOG_FILE file:ze-regex
SPAM_REGEX_MAX_* controls the maximum size of mails to process as soon as spams emails are often less than 40K.
To get more information on actions, have a look here
The syntax is explain in the default file in commentary.
For example, to reject well known words in
Subject: field, add the line :
SUBJECT 1000 (c+(1|l|i)+(a|4)+(1|l|i)+s+|v+(1|l|i)+(a|4)+g+r+(a|4)+)
ze-regex file, say it to ze-filter :
$ ze-ndc RELOAD TABLES
Filtering bodies (for examples with the same words as infra) is really fast as far as I can see on my mailhost. I use more complex expressions and ze-filter doesn't overload mailhost as milter-regex does.