I can't seem to send mail from Linux using mutt and sendmail. The linux machine is on LAN behind behind a Router, and so doesn't have a valid IP address or domain name. Does anyone know how to configure sendmail so that the various MTAs out there will believe me about who I am? Do I somehow need to relay to Qwest.net's mail router? Here is a sample message I got back from NCSU: ---- Begin Error The original message was received at Fri, 29 Jun 2001 06:35:23 -0500 from dchristi at localhost ----- The following addresses had permanent fatal errors ----- rousseau at csc.ncsu.edu (reason: 501 <dchristi at goliath.qwest.net>... Sender domain must exist) ----- Transcript of session follows ----- ... while talking to celestial-switchboard.csc.ncsu.edu.: >>> MAIL From:<dchristi at goliath.qwest.net> SIZE=578 <<< 501 <dchristi at goliath.qwest.net>... Sender domain must exist 501 5.6.0 rousseau at csc.ncsu.edu... Data format error ---- End Error