[Dovecot] dovecot vs cyrus, uw, etc.

[Tom Allison]

Scott Klein wrote:
> I've been doing research on switching our current e-mail server
> (qpopper, sendmail) to imap. The decision on which server to use is
> essentially down to Cyrus and Dovecot -- I like Cyrus' approach to a lot
> of things, but the "blackbox" nature of it makes some niceties like
> using spamassassin and procmail difficult, or at least counterintuitive.
> Dovecot seems to play nicer with other apps.
> 
> I'm a bit concerned with stability, though. Although we don't have a lot
> of users (about 60) they're all very big e-mail users -- my users rely
> on their e-mail more than on their phones. We can't afford any downtime,
> and with our pop3 server, we haven't had any.
> 
> Does anybody on this list use Dovecot to serve mission critical e-mail
> to an entire company? What kind of uptime can I expect? Is it genuinely
> ready for prime time? Has anybody here migrated from a recent release of
> Cyrus and can compare apples-to-apples?
> 
> Many thanks,
> Scott Klein
> 

I can only provide some input.

It seems to me that cyrus does have something of a black box approach to 
doing things.  However, it's still in a maildir format although not in 
the typical ~/Maildir location.

With regard to procmail/spamassassin support I have the following 
recommendation, and it can be applied to both cyrus and dovecot (I think).

You do not mention what SMTP system you are using, I will assume you are 
sticking with sendmail and changing qpopper to some IMAP server. 
However, I would suggest you consider postfix in place of sendmail.  And 
yes, it's very ready for mission critical.

There is a package called amavisd-new which allows you to set up an 
anti-virus scanner and spamassassin as an extension of postfix.  This 
can process email before it's delivered from postfix to where ever 
(procmail/lmtp/...)

This simplifies some things in that the mail, as delivered to the MDA 
has already been "bagged and tagged" as spam, virus, good/bad and you 
can use procmail/sieve equally effectively for filtering from there.

downside with cyrus-imap and sieve is that you cannot "shell" out and do 
anything else with your email, like report spam to Vipul's razor.  In 
the battle against spam, it can be very important to be able to take 
immediate actions against spam in many cases.  Procmail allows you to do 
much of this on the fly.  Sieve can't.

The other downside, for me, is that cyrus has poor documentation.

The advantage with cyrus is that it can be, from what I'm told, easily 
administered from web pages.

I'm still new with this dovecot thing and I technically haven't even 
gotten it to compile/run correctly.  However some advantages that I do 
see with it are:
~/Maildir based, so it's not rocket science.
very lean and simple to run.
procmail friendly.
awesome technical support with patient developer-dudes on hand.