[thatsaguy]

Address reputation was always big, even back then.

In the last years though, I cannot really recommend to use any of the DNSBL anymore. I've encountered more cases where legitimate servers were blocked due to netblock vicinity or indeed previous ownership than actual spam issues.

Greylisting will still catch dynamic allocations almost as effectively, while you won't reject legitimate mail due to server and/or DNSBL issues.

[_urga]

Have you tried using a quorum of DNSBL (e.g. barracudacentral.org, cbl.abuseat.org, truncate.gbudb.net) to reduce false positives?

In other words, if at least two DNSBL queries agree, then reject, or feed this information to the rest of the spam pipeline?

[thatsaguy]

This is pretty common, and systems like SA do this for you by batching responses and calculating a score.

I found this to be pretty much worthless if you already have greylisting, even for high-quality curated lists such as spamhaus SBL/XBL.