dovecot as alternative

[Jeroen van Meeuwen (Kolab Systems)]

On 2013-05-31 07:36, Klos, Paul wrote:
> So it gets a little bit more complex. I'm thinking we could have kolab
> depend on an imap server (either cyrus, which would be the default, or
> dovecot, or anything else).

Please don't do that - on a clean system, "yum install kolab" or 
"aptitude install kolab" should continue to install cyrus-imapd, as it 
is properly supported.

One could make the "kolab-imap" sub-package depend on cyrus-imapd || 
dovecot, but the preference is Cyrus IMAP. It should really only have a 
satisfied dependency if and when dovecot has been installed prior to the 
installation of Kolab.

Also, the dovecot package that gets installed should already provide the 
METADATA plugin for it. I'm not sure whether on Debian it does, but IIRC 
upstream dovecot 2.1+ should be shipping it. It could be though, that a 
./configure switch is not included in the Debian packages.

Also, Kolab is untested with Dovecot - the Kolab daemon, for instance, 
has a habit of attempting to create user mailboxes (and default folders 
when configured), for which it uses an administrator login. Dovecot, 
AFAIK, does not have the concept of an administrator login (but does 
have "login as" functionality). I'm not sure how Kolab is supposed to 
behave in this context;

- when/how does Dovecot understand that a valid login is (or is not) 
necessarily a valid mailbox, and if it creates the mailbox for the user 
on successful login, does this go for administrator "login as" as well?

- one of the features of Dovecot being the (application of) filesystem 
quota for a user (the mailbox could count towards it), in the su-type of 
unsealed system, does it need to have the mail directory created prior 
to finding the mailbox is a valid mailbox? Would this not include the 
requirement to all Kolab users to be POSIX accounts?

- Would the Kolab daemon not need to ignore the LDAP 'mailQuota' 
attribute unless the mailbox resides on a different filesystem from the 
one a home directory is on, and instead use the filesystem quota (not 
'mailQuota', if at all from LDAP), or use 'mailQuota' to set file system 
quota?

I'm willing to entertain a "--with-imap=dovecot" switch to setup-kolab 
(note I've already added a --without-ldap, a --with-openldap, and a 
--with-ad), but these things need to be figured out if Kolab is ever to 
fully support Dovecot.

When taking in to consideration how much time I have available to 
actively contribute towards full Dovecot support, I'm afraid I have to 
conclude that, unless Kolab Systems gets involved commercially, those 
that wish to run with Dovecot are largely on their own.

While I perfectly well understand some of you have a need for Dovecot, I 
suggest that, if you do and you are willing to contribute towards Kolab 
support for it but are unable to do so in code, even if just your 
proverbial $10,-, you contact Kolab Systems.

Thanks for your patience,

Kind regards,

Jeroen van Meeuwen

-- 
Systems Architect, Kolab Systems AG

e: vanmeeuwen at kolabsys.com
m: +44 74 2516 3817
w: http://www.kolabsys.com

pgp: 9342 BF08