Re: Redundant mail server

[Alvin Oga <aoga@ns.Linux-Consulting.com>]

On Sun, 13 Feb 2005, Curtis Vaughan wrote:

> Not sure whether redundant is the right word. Anyhow here's the 
> question:
> 
> We have an office in the US and overseas.
> The mailserver used by the overseas office is in the US office. Of 
> course, occassionally there may be downtime for the US office. So the 
> overseas office has this idea that we could set up a backup mail server 
> in their office. They would then use the backup mail server should the 
> server in the US office be down.

you should have 2 dns servers and 2 mail servers

dnsUS.npc-usa.com  and create dnsus.npc.uk
dnsUK.npc-usa.com  and create dnsUK.npc.uk

for US-based employee ..  
	mail.npc-usa.com 

for UK-based employee ..
	mail.npc.uk

configure the MTA to use the proper return addy 

- you can use the same domain or different domains
	uk.npc-usa.com
	usa.npc-usa.com

	( same for us.npc.uk and uk.npc.uk - sorta redundant )

- the trick is to have 2 dns servers .. one in us .. one in uk
- the trick is to use MX records for the mail server in us and in uk
	MX allows emails to go to the other server if the primary one
	goes down

- there is no special changes that needs to be done and everything
  is already automated

if the us office goes down, everything is still working at the UK office

c ya
alvin