ISC 2.2.1 tcp/ip mail problem

[Klaus Roy Poulsen]

After a recent update from ISC 2.0.2 to ISC 2.2.1 the following problem has
emerged:
  When ( trying ) sending mail via TCP/IP connections, an immediate return 
with the following error message occurs:

    550 xx at yy.zz... Host unknown

regardless of the actual host, known or unknown.

Further information:
  It did work under 2.0.2 with the same sendmail.cf, hosts etc. files.

  Other connections, i.e. rlogin telnet rcp ...., has no problems
  reaching the other machines on the net.

  Receiving mail from the other machines works ok.

  No nameserver is active ( and none is specified ).

  sendmail.cf is configured to send all mail to unknown hosts to a
  given known (gateway) host. Whether the destination specify an
  unknown host, a known host or the gateway host doesn't change the
  result ... Host unknown.

  Software configuration:
  ISC 2.2.1
  TCP/IP 1.2
  NFS 2.1


Is this a known problem, bug, feature, configuration option or ....  , and
what to do about it. Any clues?

					     Klaus

--
Klaus Roy-Poulsen   .  PHONE + 45 36 72 33 00  .  E-mail:  krp at compel.dk
Compel A/S          .  FAX   + 45 36 72 43 00  .  
Copenhagen, Denmark