Stan Hoeppner: > Michael Katz put forth on 11/30/2009 2:45 PM: > > > There are many filtering Postfix AV solutions that are far more > > efficient than Amavisd and many AV scanners that are considerably more > > scalable than clamav such. A few years ago we did some detailed testing > > between ClamAV and commercial av scanners and the difference was huge in > > terms of load reduction and throughput. In our tests we have found that > > the biggest performance limitation in Postfix for AV/AS scanning, > > assuming you have removed bottlenecks that amavisd and clamav introduce, > > is from having to copy messages out of the queue to scan. Some > > commercial email platforms allow for scanning in memory rather than > > requiring copying files and these platforms , in our test, far outscale > > Postfix for filtering over a 100 messages/second. > > I'm pretty sure I recall Wietse saying that third party software > accessing queue files is forbidden, as he provides no supported API for > dong so. IIRC, products that do this void the Postfix support warranty, > such as Mailscanner.
However, I am willing to negotiate an API that would be supported (but I don't recall getting input on that). The closest we have at this point is the Milter protocol which can inspect and update email messages on arrival, without compromising transactional safety, and with only minimal file system overhead (no copying from one file to another). > > Mike Katz > > http://mailspect.com > > The cost of a modern plenty powerful (CPU/memory) 1U server with a > couple of fast sata disks is around $1000-2000, paid _once_ with no > recurring licensing fees as all the software is FOSS, with minimal power > usage, maybe $100/year. What's the license + maintenance cost of any of > these commercial A/V solutions for *nix/Postfix? I'm just betting the > commercial A/V outlay is probably more than a 2nd box, especially over > 3-5 years. No? I think that there is no need to be hostile towards commercial solutions (or, at least, to hold IT solutions to different standards than other all the other things that we are paying for without getting upset). Wietse
