[cobalt-users] RE: Raq4 - Fail Over/Backup Email for a domain..

["Jerry Farquhar" <jerry@xxxxxxxxxxx>]

Trying to find a way of providing a means nearly 100% uptime and fail over.

Here is a thought I recently had and I'm hoping some one can tell me if this
is feasible or even possible.

I'd like to have the servers that do the DNS/MX records split/send the same
email messages to two physically different servers with different domain
names but the same exact user accounts on that should one of the email/web
servers fail the users could still send and retrieve messages from the
remaining server.

See a more graphical depiction of current and proposed arrangement below:


Existing:
=========================================================================
DNS/MX Server(s)
      |
	|
	-->-- Points to Domain "A" -> "Domain A" 		(Email and Web)


** In this arrangement when "Domain A"'s server fails users are unable to
receive or send email messages.



Proposed Idea (if feasible):
=========================================================================
In this situation Email is split and sent exactly the same to both "Domain
A" & "Domain B" all of the time not just if there is a failure on "Domain
A".

FYI #1 "Domain B" - would already have the exact same user email accounts
setup and users would have a secondary email client arrangement that would
check for messages on both servers all of the time.

FYI #2 - Part of the reason for wanting exactly the same email sent to both
domains all of the time is that if "Domain A" simply hangs and looks active
but really isn't and messages are sent to "Domain B" only on failure of
"Domain A" there's still a problem.


In Bound for: "Domain A" (Primary Web/Email Server)
	   |
	   |
DNS/MX Server(s)
	|    	|
	|	|
	|	-->-- Points to Domain "A" -> "Domain A" 	(Email and Web)
	|
	|
	-->-- Points to Domain "B" -> "Domain B" 	(Email & Web Optional)


Note: In a more perfect arrangement the Web address would fail over and
point to "Domain B" in a complete failure of the primary server "Domain A"
=========================================================================