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Why Are We on E-mail Blacklists?

Posted by Cliff on from the no-spam-from-here...honestly! dept.

LogicallyRogue asks: "I run an email server for a small webhosting company. We've crawled all around the email server to make it as secure as possible: tightened Sendmail's security, POP Before SMTP, denying non-authenticated relaying, using SpamCop DNS blacklist, etc. However, with all this in place, every few months, it seems that we have been blacklisted by some ISP somewhere. This month it was AOL. We had no warning, and we don't know why we were blacklisted. All the information we have is a single URL. We visit all the DNS blacklist services we can to be sure we are not on any of them. We send emails to the postmasters inquiring for more information (like perhaps a reason or copy of the email that made the ISP blacklist us) - however, those are usually bounced back because we are blacklisted. We've tried calling the Blacklisting ISP tech support - and usually get the stunned I-have-no-clue-what-you-are-talking-about silence. Have any other Slashdot readers experienced similar problems with blacklisting and the big ISPs?"

3 of 118 comments (clear)

  1. RBL's aren't perfect... by PunkeyFunky · · Score: 5, Interesting

    ..and as such, shouldn't be relied upon as a "oh this is definately for rejection". My firm uses an RBL as a plug in to SpamAssassin. Just being in the RBL by itself isn't enough to get rejected, but it bumps up the score a bit. Unfortunately, because RBL's are easy to slave and use, too many people rely on them, when the use is now limited. Limited by the fact that the 'big' spammers are incredibly clever these days. Having said all that, it wouldn't surprise me if AOL started blocking addresses with the '@' symbol... ;) Lee -- 'I love spam. Come get me.'

  2. openrbl.org is a useful tool by Uncle+Dazza · · Score: 3, Interesting

    This is a real problem. Many blacklists are far to eager to list an IP without real evidence of spamming.

    openrbl.org is useful for looking up your host and trying to figure out what blacklists you are on. But it is still fairly difficult to track down. Our server is listed on three blacklists there even though we have a static IP and have never emitted a single spam address. Sigh.

    The other problem I've found is that when a bounce arrives from another server that says you are blacklisted, you can't email them to find out what list they use!

    Our mail server does not use any blacklists, which is a shame because we get quite a bit of spam. But we are a business and I cannot take the risk of a client email bouncing, especially if they are innocent and the blacklist is wrong.

    What I'd like is a SMTP front end that uses blacklists to determine the likelyhood of the site as a spam source, and delay spam messages for a day or so. The idea being that many mass email programs cannot keep retrying for that long.

  3. Could be a new carreer path by acarr0 · · Score: 3, Interesting

    With all the renewed focus on fighting SPAM it has occurred to me that this could be a good business opportunity. It seems that small business could use someone who could not only help them to nail down mail servers but also someone who has experience with getting issues like being blacklisted resolved. A combination techie and advocate who knew who to call to get issues resolved quickly. Someone who has contacts throughout the industry. Anyone interested?