secondary mail server

[sonam]

We have qmail-1.3 running and would like to set it up as the secondary
mail server for one domain. We want this mail server to keep trying to
forward all the mail for that domain to the primary server in case the
primary server goes down - say for about 40 hours. This is an emergency
for us, any help would be greatly appreciated. 

Sonam Wangchuk
e: [EMAIL PROTECTED]