Fw: Blocking mail with forged/spoofed headers to majordomo lists

["dewed" <dewed @ dewed . com>]

I'm fairly new to majordomo and was curious about this failure notice
I got. Domains & usernames changed to protect the guilty. 

8< - - - - 
Failed to deliver to 'user@XYZ.com'
SMTP module(domain XYM.com) reports:
DNS Loop: MX-record XYZhosting.com points back to us

8< - - - - 

So the host has the domains MX record messed up, right?
or possibly a forward that points to itself? 

Regards & thanks for your insites.

Dewed