When I leave my machine on overnight, I've been getting the following error.

Mar 20 03:21:54 scooter sendmail[1543]: NOQUEUE: SYSERR(root): hash map 
"Alias0": unsafe map file /etc/aliases No such file or directory
Mar 20 03:22:00 scooter sendmail[1543]: NOQUEUE: SYSERR(root): hash map 
"Alias0": unsafe map file /etc/aliases No such file or directory
Mar 20 03:22:03 scooter sendmail[1543]: NOQUEUE: SYSERR(root): hash map 
"Alias0": unsafe map file /etc/aliases No such file or directory

I assume it's related to the nightly status info that mailed to root.
If I check the mail on root, it's there, so that didn't bomb.  What now?

PS.  What other window managers are available for MacBSD besides twm and
where can I get them?

Thanks,
Roger