Spam Blacklists: Useful or Useless?

Discussion in 'General' started by ZeroEnna, Oct 6, 2016.

  1. ZeroEnna

    ZeroEnna Member

    Hey guys,
    I'm facing a MASSIVE spam amount despite greylisting and stuff, and I wonder, if SBLs could help in this. On one hand, it's quite an interesting thing, I mean, you don't have to tag all spam yourself, you just query a database in the internet and poof, a large amound of spam is just gone.
    On the other hand, I also heard that these blacklists don't work very reliable, and produce a significant amount of false positives resulting in "valid" mails being rejected by the mailserver.

    So, I would like to know from you the best practice: Use SBLs or just rely on your local Amavis DB.

    Thank you in Advanced

  2. sjau

    sjau Local Meanie Moderator

    I use several blacklists. My current config looks like:

  3. Jesse Norell

    Jesse Norell Well-Known Member Staff Member Howtoforge Staff

    If you have a reasonably current postfix version and your customers all send mail on port 587, not port 25, take a look at postscreen which can use multiple weighted dnsbls to help with exactly this. Then you could need to match several lower-quality dnsbls to get blocked, or one high quality list might do it. There is sample config at (note you need to remove the MYDOMAIN.COM lines, or replace with your own).

    Spam prevention is multi-layered, and white/black lists are certainly useful to include.

Share This Page