I've been given the task of making our e-mail "more redundant". Basically, we currently have a single Courier server doing our mail storage, and serving smtp, imap, and pop3 in our main office, as well as to two (2) remote offices, and to several remote employees, travelling employees, etc. We'd like to cover the loss of our Internet connection.

I'm looking at putting a second Courier server for our domain in another office. My thinking is that the second (remote office) Courier server would "host" the users in it's office, while also having rsync'd copies of maildir's from our main office server. The main office server would still host all other Courier users, and also have rsync'd the maildir's from the remote office.

This way, if the Internet goes down at either site, only Internet e-mail at that site is affected, whereas, currently, Internet downtime creates many problems (of course).

Crazy? Perhaps, but rsync'ing shouldn't cause any problems because of the unique file names, and it's --delete option should preserve the Maildir structure across to the "mirror" server, right? Our main office only has about 100 employee's, so the T1 bandwidth should suffice...

I'm setting up a lab to test everything, including name resolution, backup MX functioning, etc. and I'm also testing the switch to Active Directory for account lookup.

Thoughts? Ideas? Anyone done similiar?

Thanks, jerry