I Have an Exchange 5.5 primary mail server (mx 5) collecting our email for 30 or so users. I would like to configure a Linux/Sendmail machine (mx 10) to act as our backup up mail server. This Linux box would be off-site. Ideally, when the primary is unavailable, I would like the Linux/Sendmail machine to collect the mail destined for our domain, queue it, and then forward it on to the Exchange server when it is online again. Is Sendmail capable of this and if so what would be the correct way to configure this? Thanks