A qmail plan

[Cogen]

I'm currently running a mail server on a Windows machine, and I would like to switch to Linux. The MTA I'm using is not compatible with Linux, therefore I think I want to switch to qmail.
My problem is that I have a lot of clients using the mail server, and I would like a backup server and a load balancing server. This obviously costs money to do, but I would like to limit the amount I spend.
Does anyone have any suggestions on how to set it up. How many servers would I need? I'm thinking I might need 4 servers. 2 of them running qmail, another 1 for a user account/file server, and 1 more that is identical to the user account/file server just incase it goes down.

Some of the things I'm not sure about are:
- Can I store user accounts and the actual email messages (file server) on a different server as the qmail servers?
- Can I make the qmail servers use the 2nd user account/file server if the first one goes down?
- Can I reduce this senario to 2 or 3 servers, still having load balancing and redundancy?
- I'm inexperienced at this, so am I even in the right ball park with this plan, or is there a "standard" method of setting up servers to accomplish this?

I realize this is a huge question, but any advise I can get would be great.

 

[thedaver]

qmail is specifically designed to NOT use different servers for the file store. DJB - the author - doesn't trust much of the mainstream NFS(-like) products and consequently, you must run one box that runs qmail, the accounts, and the mailstore. This box will also run IMAP and/or POP3 as you may require.

HOWEVER, your options for the other services expand greatly from there.

You may run multiple "gateway" qmail installs that send and receive SMTP for your domain(s) that do not have local mailboxes. You can use 2 or 3 for this task.

These gateways are also excellent points at which to install anti-spam and anti-virus screening to avoid unnecessary load on the mail server itself.

You can also build seperate boxes with Squirrelmail/Apache to provide webmail. These can use some sort of NFS *into* the mail server and/or IMAP into the mail server. Extensive use of IMAP (which is required for most webmail) can be a drag on the mail server.

I'm sure that other posters here will have other ideas...
How to build:

http://www.pipeline.com.au/staff/mbowe/isp/webmail-server.htm

Archive to search
google for mail archive of the "vhckpw" list - this is the list for building and using the vpopmail product in the link above. I KNOW that several outlines of how to build farmed installs have been discussed there.

Good luck.

Surfinbox.com Business Internet Services - National Dialup, DSL, T-1 and more.

http://www.surfinbox.com/business/

 

[BigWoody]

Starting from scratch;
I would (I did) buy the book by Dave Sill. I would (again, I did) hire the top consultant. I keep a test box around (most of the time) so I can figure things out. I subscribed to the qmail list at qmail.org. I couldn't be happier about the whole thing.
Good Luck.