Spam Control at FMP
Advisory Blocking Lists
In addition to FMP's user-tunable spam filtering system using SpamAssassin, We use a pre-filter system for controlling spam email addressed to user mailboxes which relies heavily on a set of non-commercial community-maintained advisory blocking lists. The maintainers of these lists accept reports from mail admins and mail users concerning IP addresses which have been observed to be frequent and repeated sources of spam email. Since spammers often use a collection of IP addresses within a 254-address block for sending out spam, this entire "Class C" address group containing the problem address will be listed by the blocking list service until such time as the email provider gives adequate evidence that the problem spammer accounts have been eliminated - which in some cases is never. On occasion, an ISP will provide Internet service for a customer who contracts a computer virus which, without the knowledge of the computer's owner, sends out massive amounts of spam. Blocking listings of this sort are generally removed rather quickly unless the problem is recurrent.
FMP uses these advisory blocking lists to filter out spam email before it reaches your in-box.FMP's blocking lists, and the URLs explaining them, are:
No anti-spam system is perfect. There's always some overlap between being too agressive and to lenient - between filtering out legitimate email and letting some spam through. We prefer to be too lenient, assuming that FMP's customers would rather deal with the annoyance of a few spams in thier in-boxes than with lost, legitimate email. If you want to receive a daily report of rejected spams based on FMP's sytem-wide spam blocking, please contact firstname.lastname@example.org. Likewise, if you hear from any of your email correspondants that their email is being blocked by FMP, please email email@example.com with full details of the problem. FMP survives because I can provide personalized and customized service to our small but dedicated user base, so everyone's satasfiaction with their service is important.