I'm just a zimbra beginner, so please excuse if my question is stupid.

I have some experience with NoSpamToday, which is nice antispam SMTP gateway for Windows based on SpamAssassin. It seems to me that Zimbra implementation of SA is different and not very understandable for me. I thought that SA principle is that it scores messages by series of tests which has its own scores and then message is or is not considered as spam by total score. Network tests as RBLS are part of scoring system.

Here in zimbra it looks to me that RBLS are not part of scoring. For example, when I use <zmprov zimbraMtaRestriction "reject_rbl_client dnsbl.njabl.org"> then every message, that is positively tested in NJABL is rejected. So will be rejected all messages from gmail, because it is listed there. (tested). This is not good behaviour.

I have tryied to modify /opt/zimbra/conf/salocal.cf (skip_rbl_checks, required_score, own local rules), but it does not work as expected. What are the possibilities of tweaking SA, like adding user rules, modifying scores, using RBLs and so on?

Thanks Petr.