Hi Mark

I've changed two mailservers with each around 600 mailboxes from Courier to Dovecot. Not of performance reasons (the two mail systems are imho almost equivalent in performance) but for configuration reasons. You've way less to configure on Dovecot than on Courier.

I'm using following config now: Postfix+Dovecot+Roundcube and it works like a charm.

At the end it is your decisions but for the one I took it was a good one.

Regards, Claudio

On Thu, Jun 25, 2009 at 4:33 PM, Mark Little marklittle@koallo.com wrote:

Hey all,

I know this isn't strictly related to RC only, however I was wondering if I could get some feedback from anyone who has converted from using something like Courier to Dovecot and how you have found the performance differences etc.

I am currently running Exim+Courier+RC and things work well and fast, however the userbase using the system may be increasing by a very large amount shortly and I have been looking into methods to increase/sustain performance. I have seen a few people mention Dovecot and that RC has been written specifically with it in mind, however I want to make sure its worth it before I go and start messing with a system that is working well (at present).

I have also been looking at IMAPProxy - Does anyone use this with RC? (and Dovecot ?) Any issues or things I should be aware of?

Thanks in advance!

-- Mark

---

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On 6/25/2009, Claudio Kuenzler (napsty@gmail.com) wrote:

I've changed two mailservers with each around 600 mailboxes from Courier to Dovecot. Not of performance reasons (the two mail systems are imho almost equivalent in performance)

What version of DC? If that is true then either you switched to the old 0.99.x version, or dovecot is not configured properly. Its indexing makes it - as I said - an order of magnitude faster than Courier.

On Jun 25, 2009, at 9:33 AM, Mark Little wrote:

I have seen a few people mention Dovecot and that RC has been written specifically with it in mind

I don't think that is true. It is true that the majority of people that responded to a small
survey I did on this list use dovecot. It is true that most of the devs run dovecot, so any testing they do
in the course of development is sure to include dovecot.

I'm pretty sure the devs want to make sure the IMAP server software
doesn't matter. That said, I would surmise that not much effort goes
into working around idiocycracies or bugs in specific IMAP servers
that aren't used by the devs themselves.

But using dovecot isn't a hard requirement.

I can't speak to performance differences between dovecot and other
IMAP servers, plus my user base is relatively small ( ~50 ).

Earnie Boyd wrote:

Just curious as to which version you recommend for dovecot and if you
know of a ubuntu package for it. I would like to upgrade.

Version 1.1 is definetly faster than 1.0. In next month will see probably first 1.2 release with many new features. Packages for Ubuntu http://packages.ubuntu.com/jaunty/dovecot-imapd

On Thursday, June 25 at 10:33 AM, quoth Mark Little:

I know this isn't strictly related to RC only, however I was wondering if I could get some feedback from anyone who has converted from using something like Courier to Dovecot and how you have found the performance differences etc.

I converted from using IMAPProxy+BincIMAP to IMAPProxy+Dovecot, and then shortly thereafter I ditched IMAPProxy.

I used BincIMAP originally because it was brain-dead simple to configure, and fit well into my authentication mechanism (I used a checkpasswd frontend to LDAP) and my mail storage (Maildir). However, it was *really* slow at times---particularly when doing any sort of server-side searching or sorting. That's why I started using IMAPProxy, which helped, but not much. But, silly me, I figured that was just how it was, that the speed couldn't be helped, and that Binc was as good as any other. I only migrated because Binc was abandoned by its developer.

When I moved to dovecot (back in their 1.0rc50 days), I was blown away by how fast it was. It indexes, it caches commonly-accessed headers, it does everything it can to make IMAP blazing fast. And boy is it ever! It was so fast that I tried ditching IMAPProxy altogether, and whaddya know, it didn't make a lick's worth of difference in the speed. So, out went IMAPProxy.

Since then, Dovecot's just gotten faster. It's got full-text indexing now (which it didn't at the time I started using it), and it's dramatically improved its caching behaviors too.

And on top of that, Dovecot obeys the IMAP spec more strictly than most other IMAP servers (http://www.imapwiki.org/ImapTest/ServerStatus), including UW-IMAP. Trust me when I say: give Dovecot a try. You won't regret it.

I have also been looking at IMAPProxy - Does anyone use this with RC? (and Dovecot ?) Any issues or things I should be aware of?

You can use it... but I don't think it helps much with Dovecot. IMAPProxy helps when making new connections is inefficient; but at the expense of making MORE connections. This can help if your IMAP server is slow to authenticate or slow to open new connections. In my experience, the biggest benefit from IMAPProxy was authentication speed. Often with webmail, the same user authenticates over and over again, and if your authentication method is particularly slow (Binc's was), using IMAPProxy saves a lot of time because it caches that kind of thing. But if your IMAP server is very efficient at handling multiple connections---and Dovecot IS---then IMAPProxy is unnecessary, and only serves to make your setup a little more complicated.

Hope that helps,

~Kyle

Beauty is in the eye of the beholder and it may be necessary from time to time to give a stupid or misinformed beholder a black eye. -- Miss Piggy

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