I want to test some sendmail tutorials (disconnected from any
network) using user@localhost type of addressing. I seem to be
missing some configuration steps, possible including having a real
live DNS server.

I've tried touching Hermes by setting up Outlook express accounts
for smtp.localhost and pop.localhost, but apparently that is not
enough to get the test moving.

What obvious steps am I missing and where would I find appropriate
documentation to help understand what I'm missing?