[Dovecot] [OT] Webmail Recommendation

[Mike Brudenell]

Greetings -

On 10 Jan 2008, at 21:49, Chris Wakelin wrote:

> With Dovecot's caching and indexing, things are much better, but  
> there is still a significant overhead on opening lots of  
> connections, I fear, especially for mboxes (moving to maildir would  
> help of course). I would consider using imapproxy (designed to  
> assist with this problem by caching the IMAP connections) but I'm  
> not sure whether it would help significantly.

Whatever you do, DON'T move to Maildir if you are using the Prayer  
webmail software!

We have used Prayer here for many years with the UW IMAP server  
backend and first Berkeley, then later MBX, format mail folders.

When we migrated new users to Dovecoe with Maildir folders we  
discovered that Prayer does NOT like Maildir folders.  The reason is  
that Maildir folders are "dual-purpose": each can contain any mix of  
messages and sub-folders.  However Prayer is intrinsically designed to  
ONLY work with folders that can contain messages or subfolders, but  
NOT both.  The result is that Prayer can show you the list of folders  
to navigate around, but will not list any messages within any folder.

I checked with Cambridge and this is a known and documented  
restriction with Prayer.  Their solution has been to hack Cyrus to  
prevent dual-use folders.  (Timo kindly supplied us with a patch for  
Dovecot 1.0.x to do likewise.)

We are thinking about moving to a different webmail platform soon, so  
I am following this discussion with interest.

I can confirm that webmail software that uses persistent IMAP  
connections is a big win: it not only lightens load on the webmail  
server machine but also, more importantly, on the IMAP servers.

Cheers,
Mike B-)

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