hostname and cups/mail setup

[Jonathan Walton]

I have an interesting dilemma.
  I am using cups for printing and nmh for email, and I've yet to figure
  out a setup that keeps them both happy simultaneously.  Specifically, the
  problem seems to be the hostname.

I am on a Pismo, using DHCP over airport to a Linksys AP, then to a
cable-modem for my net connection.  Other than setting up the eth1, I
haven't really done anything to modify that setup... and specifically I
have not modified my /etc/hosts, and my /etc/sysconfig/network still has
the line HOSTNAME=localhost.localdomain

The end result of this setup is that I have a hostname of dhcppc1, and no
domain-name.

  When set up this way, CUPS doesn't work, because none of the tools
  (including lpd) can run, instead giving an error of the form:
     2003-01-24-22:04:15.692 Get_local_host: hostname 'dhcppc1' bad

  If I set my hostname to something that is resolvable (such as using
    sudo hostname localhost
  ) then I can start lpd and CUPS works fine.

However, if I set my hostname to something that can be looked up, then
I am no longer able to send outgoing mail via smtp using post(nmh).
  I don't entirely know what's going on here... but if I add an entry into
  my /etc/hosts table to let the current hostname (dhcppc1) actually
  resolve, or if I set the hostname to anything else and let it resolve,
  then my smtp server (smtp.hotpop.com) no longer accepts mail from my
  machine.  It seems to allow the connection, but then just sits there
  indefinitely without transferring the mail.  As soon as I change back to
  an unresolvable hostname, things work again.

I'd love to hear a fix to this problem, but I'm just as interested in
hearing the 'standard' (if there is such a thing) way for people to set
their hostname and domain name when on an unnamed private network, such as
provided by my wireless AP [the wireless AP is on my attbi.net cable-modem
domain, but obviously the computers behind it are not].

Jonathan