on 7/8/09 6:12 PM, Stefan Förster said:
Thanks for your advice, Brad. The problem is that, due to policy reasons, outgoing mail has to pass a content filter, running locally on the Mailman box. With VERP...
Chuq von Rospach wrote some stuff in the FAQ detailing his experience with how VERP impacted performance on the systems he was managing. Of course, this doesn't necessarily apply directly to your case, but it is instructive to read.
My recollection is that, in his case, he found that without VERP he got about two recipients per copy of each message transmitted -- due to the fact that some recipients are all on the same system and only one copy is sent to that system for multiple recipients, while others get unique copies because no one else is subscribed from that system.
That meant that enabling VERP roughly doubled the number of copies of messages that had to be sent (so that each person is guaranteed to get their own personal unique copy), but that this didn't actually affect the overall performance very much (since so much of e-mail is I/O bound and waiting for the system at the other end to respond).
However, enabling VERP also meant that it was now much, much easier for the system to automatically manage bounces (a.k.a., Non-Delivery Notices, or NDNs), delivery status notices (DSNs), etc.... This made overall management of the system much easier, and greatly reduced the amount of work that the system had to try to do to parse the bounces to try to figure out which recipient(s) it was in relation to.
If you throw a content scanning system into that mix, most of the content of each of those mailing list messages will be the same, so depending on how that content scanning system is configured, it shouldn't be that much more expensive to process 100 virtually identical messages as it is to process the first message in that group.
I guess I will simply move the list server to another computer (and a different network).
OTOH, moving the mailing list function to a different server and separating that from the content scanning system is also a good idea, including lots of other reasons.
Good luck, and I hope that this works out for you. -- Brad Knowles <b...@shub-internet.org> LinkedIn Profile: <http://tinyurl.com/y8kpxu> ------------------------------------------------------ Mailman-Users mailing list Mailman-Users@python.org http://mail.python.org/mailman/listinfo/mailman-users Mailman FAQ: http://wiki.list.org/x/AgA3 Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/ Unsubscribe: http://mail.python.org/mailman/options/mailman-users/archive%40jab.org Security Policy: http://wiki.list.org/x/QIA9
