Re: Zimbra + IMAP

[Matt Mencel <MR-Mencel@wiu.edu>]

We decided from the beginning to only "officially" support the Web UI.  We have IMAPS/POPS and the Connectors available, but it's not very advertised and we always tell people "use at your own risk".  We do what we can to steer people to the Web UI.  It's upset some users, but it has helped centralize our support people....so they don't have to know how to help people configure every mail client ever invented.  The "super users" that can support themselves usually figure it out...or like the Web UI well enough that they don't mind switching.

Matt

----- Original Message -----
From: "Steve Hillman" <hillman@sfu.ca>
To: "zimbra-hied-admins" <zimbra-hied-admins@sfu.ca>
Sent: Saturday, April 19, 2008 1:51:10 AM GMT -06:00 US/Canada Central
Subject: Re: Zimbra + IMAP


----- "Robert M. Thompson" <ab5602@wayne.edu> wrote:

> Hi Steve,
> 
> We are also currently in the process of investigating Zimbra to
> replace our current Mirapoint install.  I don't think IMAP would kill
> your Zimbra setup, but I don't have any direct experience with
> high-volume Zimbra+IMAP either.  IMAP is a relatively light protocol
> and fairly efficient at allowing remote access to email.  Currently,
> we support IMAP for around 35,000 users with Mirapoint and see fairly
> heavy use with minimal impact to our servers.

If your primary usage is IMAP, you'll definitely want to grill Zimbra folks on how they think it'll hold up under that kind of load. The Mirapoint servers were built for large IMAP, so they can deal with it. Zimbra is Java based, with all connections being handled by one Java VM per mailbox server. IMAP wants to keep connections up, spinning their wheels on every open folder. That uses up valuable threads in java (one thread per connection I believe), which could quickly exhaust your resources. 

But this is mostly speculation on my part right now, because we haven't actually hit Zimbra with hundreds of IMAP connections to see how well it performs..

-- 
Steve Hillman                                IT Architect
hillman@sfu.ca                               IT Infrastructure
778-782-3960                                 Simon Fraser University
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