[msmtp-users] Mail to root

[Nathan Weston <elbows@...215...>]

I'm using msmtp on my desktop machine to get output from cron jobs, etc 
at my usual email address instead of a local mailbox.
Unforunately, cron will sometimes send email to root, and msmtp will try 
to deliver such messages to root on my ISP's SMTP server, leading to 
cranky phone calls from their sysadmins.
I can set the MAILTO environment variable in cron. But if I screw that 
up, or some other program decides to send mail to root, I'll have the 
same problem, and I won't know it's happening until the poor admin gets 
sick of it and calls me again.
Is there a way for smtp to either a) use an alias for root or b) reject 
email when the to address has no domain? Or is there some other way 
around this problem?