Courier

From Docunext Technology Wiki

We use courier to provide access to imap mailboxes, and deliver email over pop. It has worked fine for me over the past few years.

Courier Access Control Lists

Courier has some nice access controls, and I may end up using them in the future for shared mailboxes. I would also like to use them to make my email archives read only. The tool to use or this is maildiracl.

Courier supports immediate new message notification with the ENHANCED_IDLE setting. This is something I've been interest in when learning about IMAP Email.

User Databases

Courier provides a few different ways to store user information. In the past I've used MySQL, and I'd like to also try the userdb and ldap modules.

http://www.courier-mta.org/authlib/README_authlib.html#authuserdb

I'm planning to continue storing the user data in a MySQL database, but would like to export it out to a bdb flat file for everyday use.

IMAP_EMPTYTRASH

This can be a little tricky. Mail is only deleted from the mailbox after its been in the trash folder for the amount of days specified, even if the message itself is older. Also, I had to specify the trash folder name I was using: "Deleted Messages", instead of just "Trash". I included the "Spam" folder as well.

This actually does work for me and is a really great way to keep mailboxes under control.

Courier Errors

Sanity Check

This one always gets me:

##NAME: IMAP_MAILBOX_SANITY_CHECK:0
#
# Sanity check -- make sure home directory and maildir's ownership matches
# the IMAP server's effective uid and gid

IMAP_MAILBOX_SANITY_CHECK=0

The default is one, but I've never been able to get it to work. I think that this would be a good idea, but I'll have to try it later.

Quotas

I can't seem to figure out how to get quotas to work. Courier-authdaemon has access to the quota field in the database, but I don't know if it is getting used at all. I am on the topic because I'm revisiting RoundCube, the awesome email web client, and it has a quota display (actually it says "Disk usage: unlimited"). Mine always say "unlimited".

Discovered a couple of things:

Postfix is involved, and the quota values are more than just numbers - there are two values - size and number of emails, suffixed with "S" and "N", respectively. ( I need to double check that!)

Maildir Access Control Lists

maildiracl -list .maildir INBOX.Spam
owner	alr
administrators	aceilrstwx

maildiracl -set .maildir INBOX.Spam owner aceilrstwx

Links

http://www.informedemail.com