Help! Mail to 'localhost' not staying local CORRECTION

[V.I.Victor]

>My guess is that DNS was propagated and now athome.net is in the maps of 
>the DNS server you query.

Probably.  But (from orig post):

   Domain Name: ATHOME.NET
   Status: clientTransferProhibited
   Updated Date: 02-apr-2007
   Creation Date: 30-nov-1999
   Expiration Date: 30-nov-2015

whois shows an update yesterday and creation 8-years ago.

Presumably, something happened based on the update...

>Just change your /etc/hosts file, you can use a domain suffix that does not 
>exist for instance.

Yes -- that works.  I'd changed .net to .nzt and localhost works again.

I've spent the last couple hours trying to get sendmail to not do a DNS for specified-local addresses.  Lots of google-info, but none that directly works.  Much to be assimilated -- I'm pretty sure there's a sendmail solution too.