>From: Ian Zimmerman <i...@primate.net> >Sent: Tuesday, February 14, 2017 10:04 PM >To: users@spamassassin.apache.org >Subject: Fastest listing RBL ? >Given a piece of horrible spam, on which RBL is the sending IP address >likely to appear first?
>I want to rationally decide which RBL/s to consult at SMTP time. Afraid >to use all of them, not just due to false positives, but also due to >negative caching in DNS, which could affect the result when the spam is >seen by SA a bit later. What MTA are you using? Postfix is very flexible and Postscreen is powerful. It can be setup with dozens of RBLs with weights so even not-so-good RBLs can be used to safely. If you turn up the RBL sensitivity with a lot of them in postscreen, it will require using postwhite to prevent blocking legit mail from major hosting providers. In this case SA will have to handle those messages based on content. Greylisting is the best help to add a delay to give time for RBLs to list new IPs. Greylisting can be setup selectively so it doesn't slow down email from trusted senders which is the most common objection to using greylisting. I thought it would be impossible to implement it without my users complaining but I was able to do it with a little care over a few weeks. Dave
