On Feb 3, 2010, at 4:38 PM, Bradlee Landis wrote:

Actually, I was more concerned about the MTA (I think).

This HOWTO from The Linux Documentation Project can help clarify how
the different pieces of a mail system work together :

http://tldp.org/HOWTO/Mail-Administrator-HOWTO.html

I really like your application, but we are currently using openwebmail, which uses the mbox file directly. I had kind of looked at the structure of your MySQL, and saw that it had message, so I assumed it stored the whole thing. But I guess I didn't look enough, because, from what I'm guessing, it just stores flags on the messages that it has seen (such as read/unread, etc).

Read / unread is handled by the IMAP server, so that those flags
remain as you want them if you access that account from a different
piece of software. If that info was stored in RoundCube, then if you
switched to Thunderbird, all the messages would have the incorrect
read / not-read flags. Since it is stored in the IMAP server,
switching MUAs works.

There is a feature in RoundCube where it can cache message
information in the database ( not always MySQL ), but with
improvements to IMAP servers, that caching is no longer recommended.
The database schema for message caching is probably what you bumped into

We were also in the process of trying to get data replication for some mail servers in place, and so I thought if it was MySQL, it has built in replication and would make it easier. I was thinking that if RoundCube was built to go to the MBox file, move that information over to a database, then I would just take the database and copy it over, but it looks like roundcube is not going to cut it.

There are tools for syncing IMAP data between hosts, if that is what
you are looking for. Search for " IMAP replication " or " IMAP
synchronization "