Jeroen Geilman put forth on 9/22/2010 5:06 PM: > I don't know if anybody has run tests of this yet (it's still kinda > new), but it would be instructive to compare a "regular" postfix setup > (pre-postscreen) to a postscreen setup with fairly strict settings, with > respect to the load when a large spam dump hits.
As I understand postscreen... This is highly dependent on the spam source(s). If the dump is from malware spam bots then postscreen will likely help considerably. If it's coming from a large snowshoe farm(s) using real MTAs, and not listed by any dnsbls, then postscreen may not help much, if at all. In this latter case you'll be highly dependent on your content filters. So WRT snowshoe, postscreen changes the game little, unless the IPs are dnsbl listed. Snowshoe often aren't listed at all, but Spamhaus is doing better today in this regard. Invaluement's ivmSIP and ivmSIP/24 target snowshoe spam sources specifically, and would be a good addition to anyone's postscreen dnsbl config. Unfortunately the Invaluement lists are not free, although they are relatively inexpensive. They also must be hosted locally via rbldnsd or BIND (or any dns server using BIND format). http://www.invaluement.net -- Stan
