hello sir,
We are a group of administrators working on a mail server project.
We will try to explain our project completely as below:-

We are making 2 mailservers each having different hard disk. We want that Both the mail servers combiningly form a raid1 configuration.Each mail server is having their own mail boxes.Both Mailservers should point to only one hard disk .

Our main aim is that at a perticular time both hard disks should synchronise so that the mailboxes data will be same in both the mail servers.

So that if any mailserver fails the other mailserver should take the load (as it happens in raid1 configuration).

Kindly help us

thanks

Unless you can afford very expensive load balancing hardware that does these types of things for you when one fails, the other picks it up, your probably better off creating a cluster of some kind or the like.

A quick google search found this project that might help: http://www.linux-ha.org/

I'm in the same scenario ....

I have two servers running postfix/courier/mysql doing virtual hosting of email accounts/domains. I have the first mail server (mail1) doing mysql data replication and acting as a master mysql server, while the second mail server (mail2) is a slave mysql server and is instantaneously synced with the mail1's database. I'm also having to some how sync the actual user mailbox files (probably over nfs on remote file server) located in /usr/local/virtual on both servers. So I have one way mirroring mail servers, (mail1 is mirrored to mail2). As far as load balancing I'm still doing some research, but it seems like a pop3/imap proxy server would be the solution.

The proxy server is the solution for load balancing user logins:
pop3.foobar.com and imap.foobar.com both point to the proxy server which then decides which mail server to forward the pop3/imap user to.

And for load balancing incoming emails I believe setting in the domain's mail exchange records both mail servers with the same priority would balance the incoming mail.

Mainly the current problems i'm having is finding a pop3/imap proxy server that can implement rules not based on specific email accounts, and finding a way to instantaneously sync the directory /usr/local/virtual between both servers with using another server for nfs, and allow both servers to make changes to it.

If I'm wrong about anything, or you know of any solutions or have suggestions please let me know. And I will keep you posted on what I figure out.

Thanks