I am new to the mailing list and saw some talk about postgrey a couple of years ago, but nothing in the last couple of months. I am the postmaster for a medium sized ISP and we are looking to implement greylisting, as we are getting buried by spam.
I started testing postgrey in our environment, but I was wondering if anyone would share some of their tips/successes/configurations to help me along. I already had the DB climb to an insane size (1.7 GB - under a slightly different config than below) and I want to keep that value down. The DB purge of expired data was not playing well with postfix at this size.
Here is the /etc/default/postgrey config that I am testing using postgrey 1.25-1.
--greylist-action=WARN --max-age=8 --retry-window=12h --delay=315 --auto-whitelist-clients=1 --greylist-text=Busy --inet=192.168.1.1:60000
I am running postgrey on a separate server from our incoming mail MTAs. We are taking in around 350 million message a month, so I am hoping that I can get postgrey to work for us. However, I may be just too hopeful about getting postgrey to work at that level. Under this load, postgrey is consuming 1 of the 2 cpus on the box 100% of the time.
I see that the postgrey 1.26-1 is out and should have some DB cleanup efficiencies, but I (so far) haven't found much detail about what has changed and what I can expect from that.
Any help would be extremely appreciated. I am itching to turn on greylisting to save my sanity.