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 <ip.address.of.mailserver> > 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
