On Thursday, June 3, 2004, 2:38:40 PM, Joseph Kang wrote: >> 2) What the heck is SENDMAIL doing checking BLs anyway. That is a job >> for filters. (See item 1 - I suspect item 1 is mostly the case >> except for large ISPs. I get around 200 spam per day, a wee less >> now that what's his dork is in prison. If Loren and I handled our >> own SendMail we'd see 100:1 bad addressees compared to bad BL, >> I suspect.)
> Um... The ability to use DNS RBL checks have been in sendmail for quite some > time now. If you don't agree with it, take it up with the sendmail > developers. Or just don't use it. You can always not use RBLs in sendmail (or other MTA) and instead check against RBLs in SpamAssassin and then be able to adjust the scores there. Using RBLs in the MTA is a binary decision: drop at the transport level or not. > It's one more option that sendmail has to cut down on spamming. It's up to > the administrator and his/her philosophy as to whether or not to use RBL > checks in from sendmail. It's not enabled by default. Nor is there a > default list of RBLs to check. The administrator has to set that all up by > hand. > Personally, I find it easier to drop a message from a server listed in an > RBL prior to attempting delivery than doing so after delivery (for those us > who aren't using a milter). I use a fairly conservative set of RBLs with sendmail as a first processing step also: sbl-xbl.spamhaus.org, list.ordb.org, etc. I don't use bl.spamcop.net since it seems too aggressive. YMMV. > Obviously, dropping messages at the MTA via RBL has its own hazards... Yes, it can mean missed legitimate messages if the RBL entry is wrong for your users. Which is also why MTAs include a way to describe why the message was rejected so a legitimate sender or their ISP can get themselves off the RBL. >> What about if you want to use the BL as a "score" rather than a "dump on > sight?" > That's the administrator's prerogative. PERSONALLY, I prefer to dump on > sight. :) > Cuts down on a ridiculous amount of e-mail and cuts down on the amount of > junk that gets passed on to our MS Exchange server. Yes, and using RBLs in the MTA also cuts down on the messages even reaching SpamAssassin, which can save quite a bit of CPU. Like anything else using an RBL in the MTA has tradeoffs that the system administrator needs to be aware of, including false positives, choice of lists, etc. That said, they work fine for many people. Jeff C. -- Jeff Chan mailto:[EMAIL PROTECTED] http://www.surbl.org/
