[Mailman-Users] Name or service not known

I'm setting up mailman/exim and when qrunner runs, no mail goes out. Nothing appears in exim_mainlog but $config/logs/smtp says:

All recipients refused: (-2 'Name or service not known')

I can't figure where this is coming from. If I go to $config/qfiles, the message waits there.

I can push the message out by using "exim -t < the_message.txt" so I think exim is ok. All my "sendmail" files are linked to exim. What else?

Anyone have an idea what I've done wrong?

Thank you,

Marilyn Davis