[nflug] cyrus vs dovecot

[Darin Perusich]

I've been using Cyrus for the better part of 5 years so needless to say 
I'm biased. It's superfast, bombproof, auto deletion of messages, 
supports shared mailboxes, the list goes on and on. It's not trivial to 
setup but once you get it up it requires zero baby sitting. It also 
doesn't hurt that the lead developer is a colleague of mine and who 
lives in Buffalo!

My cyrus server has 374 days of uptime, average load is 0.21, 5000+ 
mailboxes, 550000+ messages, with about 50 continuous connections. The 
machine is 3.0ghz/dual-proc, 8gb of mem, RAID5 SAN storage, running 
openSUSE 10.2. This machine is a powerhouse but I built it to last for 
the next 3-5 years and email is really important around here so it needs 
to be.

Cyrus a closed system, meaning it's only meant to be accessed via an 
IMAP client or the admin tools. You can't just jump into /var/spool/mail 
and check out a single mbox file. It supports LDAP via SASL but I've 
found the easiest way to set it up is to configure the underlying host 
as an LDAP client and to configure SASL to use PAM. Are you only 
providing imap/imaps or pop3 as well?

Someone asked this very question on the Cyrus mail list last month, 
apparently he was after "unbiased" answers ;-). Checkout the threads 
here. 
http://lists.andrew.cmu.edu/pipermail/info-cyrus/2008-August/thread.html

You mention that you plan on using procmail. Cyrus uses Sieve for 
message filtering and procmail is simply not supported. The best way to 
manager Sieve filters that I've found is the avelsieve plugin for 
Squirrelmail.

One recommendation I would make is separating your spam/virii filtering 
  and the imap server, amavisd-new is expensive in terms of resources 
and is better off on its own machine. I'd have your MX relays on the 
internet run amavisd-new and filter/tag all messages BEFORE they get 
inside, relay to an internal smtp relay which may filter/tag w/ 
amavisd-new which then sends mail to the final destination, your imap 
server. Your users, internal servers, and wembail send mail to the 
internal relay which either relay mail to imap or out to the intended 
recipient.

Hope this was helpful.

Eric Benoit wrote:
> Hi just wondering if people have a preference, which would/do you use 
> and why?
> 
> cyrus or dovecot
> 
> I'm going to use postfix,procmail,amvis,spamassin,ssl/tls
> 
> also authenticating with a ldap server, and I'm pretty sure that I want 
> mail folders created on the email server
> 
> Thank you for your responses,
> Eric

-- 
Darin Perusich
Unix Systems Administrator
Cognigen Corporation
395 Youngs Rd.
Williamsville, NY 14221
Phone: 716-633-3463
Email: darinper at cognigencorp.com