On Thu, Jul 31, 1997 at 02:20:58AM -0600, Tracy J. Di Marco White wrote:
> 
> This was a much "neater" trick, as I received the *same* spam... from
> KAT@iastate.edu.  I didn't realize this was possible, but it looks
> like it adopts the host name from the final destination mailhost.

That's actually a sendmail config option. I forgwt which, I don't deal
with sendmail often and the options are confusing to me :) This option
appends the local mail domain to an address that doesn't have one
in it. So any mail which says From: x will be expanded to From: x@yourdomain

- Frank