SpamAssassin Basic Rule set
required_hits (default: 5)
Set the number of hits required before a mail is considered spam and tagged [***SPAM***] in the subject line. n.nn can be an integer or a real number.
NOTE THIS ISN'T THE SCORE AT WHICH MAIL WILL BE REJECTED OUTRIGHT; THAT IS SET SEPARATELY IN EXIM CONFIGURE FILE.
5.0 is the default setting, and is quite aggressive; it would be suitable for a single-user setup, but if you're an ISP installing SpamAssassin, you should probably set the default to be more conservative, like 8.0 or 10.0. It is not recommended to automatically delete or discard messages marked as spam, as your users will complain, but if you choose to do so, only delete messages with an exceptionally high score such as 15.0 or higher.
Used to specify addresses which send mail that is often tagged (incorrectly) as spam; it also helps if they are addresses of big companies with lots of lawyers. This way, if spammers impersonate them, they'll get into big trouble, so it doesn't provide a shortcut around SpamAssassin.
Whitelist and blacklist addresses are now file-glob-style patterns, so firstname.lastname@example.org, *@isp.com, or *.domain.net will all work. Specifically, * and ? are allowed, but all other metacharacters are not. Regular expressions are not used for security reasons.
Multiple addresses per line, separated by spaces, is OK. Multiple whitelist_from lines is also OK.
The headers checked for whitelist addresses are as follows: if Resent-From is set, use that; otherwise check all addresses taken from the following set of headers:
whitelist_from email@example.com firstname.lastname@example.org
Used to override a default whitelist_from entry, so for example a distribution whitelist_from can be overriden in a local.cf file, or an individual user can override a whitelist_from entry in their own user_prefs file. The specified email address has to match exactly the address previously used in a whitelist_from line.
unwhitelist_from email@example.com firstname.lastname@example.org
whitelist_from_rcvd email@example.com sourceforge.net
Use this to supplement the whitelist_from addresses with a check against the Received headers. The first parameter is the address to whitelist, and the second is a domain to match in the Received headers. This domain does not allow globbing, and must be followed by a numeric IP address in brackets in the Received headers.
whitelist_from_rcvd firstname.lastname@example.org example.com
whitelist_from_rcvd *@axkit.org sergeant.org
Used to override a default whitelist_from_rcvd entry, so for example a distribution whitelist_from_rcvd can be overriden in a local.cf file, or an individual user can override a whitelist_from_rcvd entry in their own user_prefs file. The specified email address has to match exactly the address previously used in a whitelist_from_rcvd line.
unwhitelist_from_rcvd email@example.com firstname.lastname@example.org
Used to specify addresses which send mail that is often tagged (incorrectly) as non-spam, but which the user doesn't want. Same format as whitelist_from.
Used to override a default blacklist_from entry, so for example a distribution blacklist_from can be overriden in a local.cf file, or an individual user can override a blacklist_from entry in their own user_prefs file.
unblacklist_from email@example.com firstname.lastname@example.org
If the given address appears in the To: or Cc: headers, mail will be whitelisted. Useful if you're deploying SpamAssassin system-wide, and don't want some users to have their mail filtered. Same format as whitelist_from.
There are three levels of To-whitelisting, whitelist_to, more_spam_to and all_spam_to. Users in the first level may still get some spammish mails blocked, but users in all_spam_to should never get mail blocked.