[QUOTE=cyberiad;26840]That was not an easy decision, but with planning a product for a life time of 10+3 years we had to take a decision which solution should be picked for SLES 12. One reason was the feature set. For example dovecot supports maildir, has cluster support included, backup can be done without stopping the server and many other. Very important is also the maintainability. Dovecot is actively developed and doesn’t have as many security issues as cyrus. Last but not least it is already used by many users and companies.
If you are interested in how to migrate from Cyrus to dovecot there is documentation available for that:
http://wiki2.dovecot.org/Migration/Cyrus[/QUOTE]
Hi,
thanks for the answer.
I tried Dovecot on the machine (PC with trial SLES12). I had there cyrus builded from src.rpm and some mails. My mail has about 8000 mails in the inbox and about 20 000 emails in others folders. As a client we use mostly Squirrelmail. Loging to the Squirrelmail to cyrus was nicely fast.
I migrated to the dovecot by the cyrus2dovecot script, changed type of the imap server cyrus->dovecot in the Squirrelmail’s config and tried to log in… Stopped cyrus, started dovecot…
Loging to dovecot is too slow, Apache2 process takes 99% of the CPU, minimum disk I/O. After 90 seconds (PHP limit) isn’t a web page completed. - EDIT - I FOUND THAT I’VE SOME CONFIG ISSUES WITH SIEVE, AFTER DISABLING “AVELSIEVE” PLUGIN IN SM A PAGE IS OPENED QUICKLY. I MUST SOLVE THAT, MY MISTAKE
So it is a fast (very fast) comparsion of the cyrus/dovecot on the same machine. Cyrus’s config is fast and easy, configuring dovecot takes more time.
Anyway - I didn’t found that cyrus2dovecot could not import to dovecot sieve script. Seen/sub are OK, I tested it, but user’s sieve scripts ?
We’ve 3000 of the mailboxes in the cyrus, sizes (quota) is about 1GB, and each user has thousands of the mails (we also have an account with 220 000 mails in inbox and in the mail archive on another server we’ve 590 000 emails) It is reality.
And at the end one note - cyrus is live too, after that years it may’ve evolved to very stable. Issues ? Aren’t they fixed ? Or what they aren’t ? Dovecot may’ve issues too, of course repaired. All programs are made by humans, that make mistakes 
So what are real cons for us and usefull reasons to migrate to dovecot ? Cyrus is made on the college and they’ve more mailboxes than us :). Of course, we plan to create cluster, I’ve tested 2 node “cluster” with drbd+ocfs with cyrus. So is it more easy with dovecot ? Do you’ve some whitelist or study ? I’ve found some comparsion, cyrus is quite better about speed :
https://www.os3.nl/_media/2012-2013/courses/rp2/p54_report.pdf
Just asking, If anybody has some experiencies he can share
Thanks and best regards
J.Karliak