We have Zimbra 3.1.4 up and running, despite a few problems here and there on the lan segment all seems ok.

However we have a big problem with our distant sites connected via ADSL... the entire zimbra webmail experience is SLOW : examples, can lag up to 10 seconds to read an email, and up to 15 to get into the calendar.

What we've noticed so far :
- our adsl lines are not saturated (bandwidth is OK, checked through tcpdump, ethereal, iftop...), main ADSL upload is 700kbps and is never 100 percented.
- firefox does it only slightly better in terms of performance
- client cpu (FF or IE) during the lag time is at 100% (while the zimbra server is coping just fine with a .3 max load, generally at .1 !) the systems are XP SP2 2.6Ghz.
- installing squid helps caching some of the gfx

The zimbra server is
- Zimbra 3.1.4 / fedora core 4
- 2Gb RAM
- 2x 2.8 Ghz Xeon procs
- Raid 5 sata subsystem
- Gigabit ethernet switched, not that that would do anything for ADSL )

Thanks for any help/tuning ! if you need any other info I've missed out, no problem.