[Dovecot] Cyrus vs Dovecot

[Ed W]

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.  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