I tried that and it didn't fix the problem. It may be a syntax issue. If anybody can send me the syntax, and any other related syntax to add, assuming the smart host is mail.domain.com and the listserv/sendmail server is listserv.domain.com that would be appreciated.

-----Original Message-----
From: LISTSERV site administrators' forum [mailto:[log in to unmask]] On Behalf Of Nathan Brindle
Sent: Wednesday, October 07, 2009 10:05 AM
To: [log in to unmask]
Subject: Re: smart host question

At 09:05 AM 10/7/2009 -0600, you wrote:
>I am setting up a listserv server on a linux box with sendmail and a smart host. It seems to be working, except that when mail bounces, sendmail generates a bounce message to the list owner, which is going out to my smart host, then back to my list. The problem is that my smart host sees a loop and kills  the message. I think the problem is that I need to configure sendmail.mc to send local mail to the local machine. Does anybody have some syntax I can try to make this happen?
>Thanks,

Disclaimer:  I am not a sendmail expert by any stretch of the imagination, so it might make sense to see if one of the actual sendmail experts here has any input :)  However,

http://www.faqs.org/docs/linux_network/x15291.html

page down to "18.8.3. Using a Smart Host"

The solution there seems to work for me.  

Nathan