Yesterday the result was that Sieve scripts could be put in place by the system administrator and they work. Needless to say that’s cumbersome and we want users to handle it themselves.
To avoid all possible issues with opening up FTP / DAV / whatever, the clowns at Dovecot and the ietf have decided to create a new protocol for it. Currently still a draft, but it will be an official protocol called ManageSieve.

For Dovecot 1.2 it is still required to patch dovecot and then install the managesieve service. Feeling adventurous I’m going for the bleeding edge version again
First the patch:

After upgrading to the new dovecot package we still have to put the managesieve service into place. Which we have to build first.

Install the package and we’re almost done. All that’s left now is some configuration and kicking of services.
As described here the biggest thing we need to do is add managesieve to the protocols line in /etc/dovecot.conf. Like this:

By default this will steal port 2000 for incoming managesieve connections, but you can change that and a few other things in the dovecot.conf file if you like. Just add a section like this:

And obviously you need to uncomment and change whatever you want to have broken . I decided to stick to the defaults except for the log string.
After these changes give a good hard kick to your dovecot daemon (since the binary changed with the patch I’m sure a HUP won’t cut it) and see what happens.
Don’t forget to open up the managesieve port (2000 by default) in your firewall!

Let’s see if it works:

Looks good! Time to let users have some fun with molesting their stuff through Sieve
A quick test with the thunderbird sieve addon:

Thunderbird Sieve Plugin 1

Thunderbird Sieve plugin - edit script

Works like a charm. And yeah, those warnings can be ignored, they’re there because of my meddling with scripts yesterday. How should I know it had to be a symlink :-p
(after this session it was indeed a symlink, hitting the ‘active’ button made it so).

The problem: First of all, Courier is a piece of shit. The various parts of it have broken in various ways over the years (authd hanging for no apparent reason or suddenly eating a ton of memory, stuff like that). Not only that, but they decided that vpopmail wasn’t worth supporting anymore, so their latest release of courier-authlib simply doesn’t handle vpopmail anymore. (don’t ask me why, can’t find any details on it).
Second of all, it would be cool to give our users the ability to create their own custom mail filters on our server. Stuff that you can do in thunderbird or through webmail, so they can setup their mailbox filters and vacation messages and whatever without me having to help them. (well…. we’ll see about that). Needless to say we could do that by giving them access to the .qmail files, but those are way out of their league. Not only that, it would be a security nightmare. So to solve that, we’re trying the Sieve disaster. I mean language… or something.

Getting rid of Courier is really simple. Simply pull the harddisk out of your server and shake it a few times, then step on it and throw it out of the window (while still standing on top of it of course). If you did it properly you should now be wondering why the hell you follow instructions without thinking. However, if you do have a brain, you might want to shutdown the courier-imap* and pop* services and remove them from your disk. Tada.
Personally I replaced the pop, imap and auth services with Dovecot. If you’re running qmail like you’re supposed to this is pretty easy. Check out this page by John Simpson for details on that. Instructions for vpopmail included. (thanks again John!)

Now for the interesting part. Getting Sieve to work. I decided to get the latest shiny version from their hg repository, but feel free to take the latest stable version instead.

Now we still need to enable it. Make sure your /etc/dovecot.conf has a section like this:

Easy. This should make the /usr/libexec/dovecot/deliver program able to verify the account information of a requested user against the vpopmail database and it instructs the local delivery part to use the sieve plugin. (which I’ve configured some paths for).
However, next part literally took me hours to figure out. I wanted to use the Dovecot LDA only for my test email account. So I created a .qmail file for my user – according to their wiki :

According to their wiki, this should be the correct way to invoke the deliver program. So I send a test mail to benv-test@benv.junerules.com …. nothing happens. Nothing in logs, nothing.
Oh that’s a lie, the error log says:

Of course it doesn’t work yet, I haven’t put a sieve filter in place yet. So I put a simple reject filter there so I know it works when it does
This is the contents of a file ~vpopmail/domains/benv.junerules.com/benv/.sieve/dovecot.sieve. Corresponding with the dovecot.conf plugin settings.

I send another mail. Same stuff in the logs. Mhm… more debugging would be great guys. I have no idea if it loads a sieve filter, from what directory or if it does anything at all! GRRRr.
After a lot of cursing and throwing with plants and cats and hammers, I went through the mailing archives from the John’s qmail-patch list and found a snippet from someone else that set up something similar. Apparently the way to invoke the deliver program is different. Because I use the qmail extension addresses, benv-test@benv.junerules.com was given as user. However, vpopmail only knows about benv@benv.junerules.com, so it failed. Blegh.
So for now I decided to use the solution offered by the mailinglist:

A little explanation on the environment variables. Normally when I send a message to benv-test@benv.junerules.com they look like this:

The DTLINE rewrite isn’t strictly necessary but looks a bit nicer in the logs. However, the EXT@USER part should not contain all the extensions since they won’t resolve to a vpopmail user.
With the rewritten .qmail file I send another test email. Here’s the log:

Woohoo, it rejected!
So Sieve works. Next thing to do is to get ManageSieve up and running and test it with thunderbird and some sieve addons
But that’s a rant for later, my eyes are collapsing.