guys -- Is anyone on SPAM-L, and following this thread? (I received this forwarded, I'm not subscribed there)
--j. ------- Forwarded Message From: Matthew Sullivan <[EMAIL PROTECTED]> Date: Sep 28, 2007 8:13 PM Subject: Open letter to the SpamAssassin maintainers. To: [EMAIL PROTECTED] I'm posting publicly because I'm not subscribing to yet more mailing lists and this should get public comment/have public review, and if nothing else serve as a warning to other oblivious SpamAssassin users. Recently I have had to spend a great deal of time working out what is wrong with a number of SpamAssassin installations. The installations are both medium and small, in each case the SpamAssassin installations have become significantly inaccurate and in the case of the larger systems been the cause of several outages relating to load. I won't go though all the details of the investigation just get straight to the cause.... Spamhaus DNSbl lookups, by default these are turned on, and Spamhaus are now charging for use. Their claim of "we only block people that should be paying for lookups" is lame, tiring, and just doesn't fly. I don't use Spamhaus for blocking as it doesn't pickup anything else over the freely available DNSbls out there, and the number of spam bots hitting my mail server is fairly significant (upto a maximum of 440 messages per minute according to my "mailgraph". I have two of my spamassassin installations are nothing more than a user with a home DNSbl hosted domain using a local DNS cache, both of those installations are now blocked by Spamhaus (I have others that are significantly larger). All lookup requests go via a local BIND based caching resolver and lookups to Spamhaus are only for SpamAssassin. The number of lookups performed by SpamAssassin is quite typical of a home user hosted *single* domain and therefore I can only assume this is an issue that will be affecting affecting all the SpamAssassin default/recommended installations. Suggestion for SpamAssassin is to place Spamhaus in the config as disabled by default as they do with the MAPS list(s) with the reasoning that Spamhaus is now a pay-for-use DNSbl. From their read me: Disabled code ------------- There are some tests and code in SpamAssassin that are turned off by default: experimental code, slow code, or code that depends on non-open-source software or services that are not always free. These disabled tests include: - DCC: depends on non-open-source software (disabled in init.pre) - DomainKeys: experimental (disabled in init.pre) - MAPS: commercial service (disabled in 50_scores.cf) - TextCat: slow (disabled in init.pre) - various optional plugins, disabled for speed (disabled in *.pre) To turn on tests disabled in 50_scores.cf, simply assign them a non-zero score, e.g. by adding score lines to your ~/.spamassassin/user_prefs file. Spamhaus lookups are by now 'slow code' (~20 seconds per lookup == 20+ seconds per message) and has been the direct cause of the various systems I maintain going down under load. Before Spamhaus attempt to debunk my claims with "you are a large user", the busiest of the home DSL mail servers is currently showing the following stats: Daily Average messages processed via SpamAssasin: 3.52 msgs/min Weekly Average messages processed via SpamAssasin: 4.14 msgs/min Monthly Average messages processed via SpamAssasin: 3.82 msgs/min Yearly Average messages processed via SpamAssasin: 3.22 msg/min Max processed via SpamAssassin in the last 24 hours: 177 msgs/min Max processed via SpamAssassin in the last 7 days: 177 msgs/min Max processed via SpamAssassin in the last month: 182 msgs/min Max processed via SpamAssassin in the last year: 192 msgs/min This mail server is for a domain with 8 user accounts, and rejects mail at SMTP for bad DNS, SORBS lookups, CBL lookups, bogons lookups, NJABL lookups, DSBL lookups, non-existant user accounts and other reasons. SpamAssassin processing, and therefore Spamhaus lookups is post accept ONLY. Regards, Matthew
