Clustered SMTP Service doesn't always start

Hello,

We have a couple clustered Windows Server 2003 servers running IIS, FTP,
SQL Server, and SMTP. I believe the cluster was originally configured by
Dell, from whom we bought the hardware.

The problem is that the Clustered SMTP Server doesn't start
automatically. When it's not started, mail isn't delivered. And it's
like it doesn't even try to start: no error messages in the event log or
anything. The Default SMTP Virtual Server starts fine. If we manually
start up the Clustered SMTP Server, mail delivery starts working
perfectly again (at least until the next time the cluster switches or
the machine is rebooted).

We have never worked with clustered servers before so maybe there is an
easy fix for this... we just can't find very much information about this
problem on the Internet. Hopefully someone out there can help us!

Thanks,
EA