Atomicorp

How can I set up a backup mail server?
I have a customer who has his own mail server (I host only domain and DNS). He asks if I can host a backup mail server in case his mail server is down.
How can i do this? Is it possible with Gamera?

Yeah thats what PG is really based on, its called a smarthost in the mail world. If his system is down it will spool mail for it until its back up again.