Ed W a écrit :
Mathieu Kretchner wrote:
kbajwa a écrit :
Hello:
I think you are missing a point which is most important, i.e., what type of support Cyrus vs Dovecot offers. In my experience:
Cyrus = 0 Dovecot = 100
My personal experience.
Kirt
I guess you've right but I can't post this answer at Cyrus mailing list. I'm just trying to have my own opinion of imap server and I already have sarcastic answer on the cyrus mailing list !
Reading the cyrus list I think the above quote might be a bit unfair and accidently crossposted?
In any case I only have experience of dovecot and it's used in some larger installs such as the old webmail.us, now 1&1 (I believe). I think your installation is probably large enough that you might want to do a trial migration of a couple of accounts and see if migration is a problem.
I'm trying to migrate my own account from cyrus to dovecot with the 2 tools which seems to fit the most my needs :
cyrus2courier : Work fast and well but I must use cyrus2courier-1.5.ts and I have 2 problems with it : falg unseen (or seen if I want) for all e-mail / Sub folders of Inbox are invisibles (I see them on the File System) !
imapsync : Must add a transition configuration to dovecot in order to have user passdb file (or master user) but once done it's ok and work correctly. I've just tested a transition and I'm happy to see it keeps all flags (seen/unseen too) and timestamp but as cyrus2courier, I can't see my inbox sub folders although I could see them (full) on the File System?
Certainly for all new servers I would STRONGLY recommend some sort of virtualisation option (I use linux vservers, lots of other options available). This makes it fantasically easy to boot up (say) three instances of your target software installation, perhaps all with different configuration options and compare them easily. I used this as a solution to migrate from Courier and also recently when I was migrating from 32bit to 64bit guests - essentially you spin up your new guest, get it all ready, test it like made and then in a couple of seconds you can down the live guest and boot up the new guest. I separate out all signficant data from the guest partition so try to keep the actual installations under a couple hundred MB each (even that feels bloated, but hey) and this makes it simple to boot up a copy of a guest to test some change without having to copy too much
I personally picked dovecot because I worried about the horror stories I read about with cyrus. However, both are clearly the two best options available for opensource solutions right now and both are used in large installations so you should be very happy with either.
With regards to functionality it would appear (I don't use cyrus) that cyrus has more "admin tools" to do stuff, but Dovecot is built to be more "hackable", for example you can easily run a script before each (imap, etc) login and hence do some very advanced stuff through that route. Plugins also appear to be quite easy to write to extend dovecot in new directions
On the cyrus list they mentioned email retention policies. Now some people are going to say that this is really a job for the MTA (postfix/sendmail/etc). However, you have some plugins which might get you partly towards solving that need, but nothing out of the box which would give you a cast iron (stand up in court) kind of archiving control. However, you can get close I think
Ed W