Stop/block relaying e-mails to a specific address

[wizbones]

All your sendmail questions can be answered at http://www.sendmail.org and more than likely you'll find a more specific answer at RedHat.

Course you probably knew that already and just wanted a quick fix right? But I didn't give you one  :P

If'n you don't figure it out repost and I'll dig it up for ya. I myself use Postfix it's much easier to config.