Hi Steve, breaking the RFC by guessing how a spam issueing address might look is not good.
Better is to reject a spam mail directly during connection phase, because once your mail server has accepted the mail, you _must_ deliver it to the user anyway (with special tags i.e.), because of data protection laws! Even if you bounce it, you must inform your user, but moreover, this bounce will hit the wrong sender in most cases or will be sent back to your server due to unknown sender. Most of the spam is issued by robots working on hijacked Windoze-PCs and is sent without using standard mail protocolls - re-trying delivery i.e.. So greylisting is doing a good job, but binds many resources (database processing, disk space etc.) Fortunately there's an easy and very efficient check to determine early, if a mail comes directly from such a robot by using the qpsmtpd plugin require_resolvable_client *) Please have a look at my spam statistics **): Nearly 3/4 of all mails are rejected by require_resolvable_client, 15 % is blocked by using the DNS-based anti-spam-service of the german IT-journal "iX" and 10 % are suppressed because they're addressed to a non-existent user (never use catch-all addresses!). The amount of accepted mails is less than 2 % ! Some of them are still Nigeria connection messages, but they're sometimes funny to read ;-) But all that virus-, viagra- or casino-stuff is rejected successfully without using heavy-weight spam or virus filters - until now... mfg. Ernesto *) http://www.hjp.at/projekte/qpsmtpd/require_resolvable_client **) http://dienstleistung-kultur.de/spamstat.shtml -- ______________________________________________________________________ Dienstleistung Kultur Ltd. & Co. KG Lützenstr. 10, 10711 Berlin Telephon +49-(0)30 - 89 09 56 59 Prokurist Ernst-J. Johnsdorf Faksimile +49-(0)30 - 89 09 56 60 HRA 41207 Berlin-Charlottenburg http://dienstleistung-kultur.de USt-IdNr. DE 261 999 858 mailto:m...@dienstleistung-kultur.de ______________________________________________________________________ Dienstleistung Kultur Ltd. 27, Gloucester Street, London WC1N 3AX Companies House, Cardiff, No. 6512436 Director Ute-I. Pehlke ______________________________________________________________________
