Scott Silva wrote:
on 5-21-2009 11:33 AM Seth Mattinen spake the following:
V S Rao wrote:
Hi Timo,
Thanks for the response. Apologize, but my responses are going to be a bit lengthy.
I have migrated from uw-imap to Dovecot for POP3 & IMAP service. I run webmail using squirrelmail. When running uw-imap I used to run up.imapproxyd on the webmail server for faster responses. After migrating to Dovecot, I find that up.imapproxyd does not work well with dovecot. Why not? Here are my observations. I have around 6000+ mailboxes and roughly the same number of users. Earlier the mail server (running sendmail + uw-imap for POP3 & IMAP) would have around 80 pop3 connections (peak) and around 300 IMAP connections, concurrent. (ps -aef | grep imap | wc -l or ps -aef | grep pop3 | wc -l). There have been cases where I have observed upto 500 concurrent IMAP sessions.
The IMAP connections are from a webmail server running Apache with Squirrelmail. The observation was that response was slow & so based on the suggestion on Squirrelmail for performance improvement we have installed up-imapproxyd on the squirrelmail machine. There was a significant improvement in the response times for the users, because of caching.
After that I encountered some strange problems of POP3 timing out for users (earlier I did post that problem in this forum). I opened a ticket with Redhat and naturally they refused to support me with uw-imap running. So switched to Dovecot 0.99.x (I run the server on RHEL 4.0 and that is the max version supported by Redhat for that version). Ever since I did that POP3 works fine but now webmail is almost not available to the users. People usually get "connection dropped by IMAP server". However the IMAP server seems to work fine. Checked through manual "telnet
143 & also through other client such as outlook & Thunderbird. I realize you're using 0.99 because it's "supported" by RedHat, but in reality it's absolutely ancient history. There have been far too many performance enhancements/fixes between then and now to even begin to list.
~Seth
Besides, he didn't go to RedHat for support anyway. He came here. And here says start with at least the latest 1.0 version, or maybe even 1.1. You can get it from atrpms.net if you want an rpm.
Yes, that too. My point was not to judge Dovecot's performance based on a 0.99 version. ;) I've successfully used several versions of dovecot 1.1.x with imapproxyd and IMAP-only webmail clients.
~Seth