More about distribution lists

[peng1can]

The final thing I need to get going before my zimbra conversion is complete is mailing lists. We're currently using Sympa (which is written in perl and has a SOAP interface, so I'm surprised there isn't more interest in having this intergrated in Zimbra rather than Mailman...), so I'm primarily wondering if anyone has successfully set this up yet and has some hints.

Equally as important is dealing with our internal, global distribution lists (faculty, staff, all employees, all students, etc). These are currently populated in Sympa as LDAP queries and the lists have 2000-6000 local recipients. The problem I'm having at the moment is that when someone sends a message to these lists, it essentially DoS'es Zimbra... load averages races up around 20 and the servers slows down significantly. If we have the misfortune of people hitting 2-3 of these lists at the same time the server slows to a crawl.

Has anyone found a "sweet spot" for the number of recipients per message to keep Zimbra happy, but still make effective use of the single instance message store so that we're not delivering 5000 copies of the same message. Would I be any better off converting these lists to distribution lists inside Zimbra itself and managing the population via a script?

Any suggestions are appreciated!

[jholder]

Zimbra's distribution lists are great. If you can, I'd suggest you move over to them.

In either case, you'll have to manually edit/manage the list. Just keeping the lists in Zimbra, doesn't mean that the list is automatically updated.

[Krishopper]

What kind of hardware is your Zimbra machine on?

I'm going to start by assuming most of your CPU load is coming from the spam scanning of each and every one of those messages. amavisd/SpamAssassin running against all of them as they come in for each user. Perhaps there is a way you can get it to bypass checking those messages when coming from Sympa into Zimbra?

For typical mail traffic (Assuming no lists are getting posted to), what kind of traffic does the server see? messages/min?

[peng1can]

The mailbox server has four 2.2Ghz Xeon cores and 8GB RAM. MTA/Spam services are on another box, and it's the mailbox server that gets overloaded. I've tried this both with sympa configured to allow as many as 2000 recipients per message or as few as 50. The latter works much better, but still places a noticeable lag on the server.

I think we're doing about 300K messages per day normally, and as part of our transition, we still have a separate postfix/spamassassin MTA in front of the pair of zimbra filters for external traffic, so the zimbra MTA shouldn't be working that hard on spam.

I could probably make do with the Zimbra distribution lists if the internal lists were all we had, but I think people are still going to want archives of those lists, and we will still have a handful of public lists that zimbra can't really handle. So it seems silly to hack a pseudo LDAP setup into zimbra when sympa gives it to us so easily.