Sendmail question

[Noah Davidson]

I have set up a new FreeBSD box as mainly a backup mail server, although it is primary for a couple of domains.  It is running sendmail 8.13.3 and it works fine, except for all the spam that is being sent to it to bad email addresses.  I have aliased the root account to an email group on another server so that someone reads the root mail.  The problem is that all the mail that spammers are sending to address that do not exist get bounced and the root account a notification (I believe it is the postmaster alias which is aliased to root).  Is there any way to not have these notifications sent out.  They are filling up the mail boxes.  I just want the return to sender, but not to the root / postmaster as well.  I have tried using the confCOPY_ERRORS_TO in my .mc file, but that just sends it to an additional account as well.
 
Any help would be greatly appreciated.
 
Thanks
Noah Davidson