exim4 error?

["Richard Lyons" <richard@the-place.net>]

I got no reponse at all previously -- perhaps too general a question.

Does anyone recognise this set of messages on /var/log/exim4/mainlog:

2007-05-05 13:35:42 1HkJUE-000170-0o ** --@the-place.net: Unrouteable address
2007-05-05 13:35:42 1HkJUE-000170-0o ** hdrs@the-place.net: Unrouteable
address
2007-05-05 13:35:42 1HkJUE-000170-0o ** -r@the-place.net
<-R@the-place.net>: Unrouteable address
2007-05-05 13:35:42 1HkJUE-000170-0o ** delay@the-place.net: Unrouteable
address
2007-05-05 13:35:42 1HkJUE-000170-0o ** failure@the-place.net: Unrouteable
address
2007-05-05 13:35:42 1HkJUE-000170-0o *> someone@domain.tld R=smarthost
T=remote_smtp_smartho
st H=smtp.bytemark.co.uk [80.68.81.166]

I don't see what is happening but this is what I get when I try to mail out.
No error is indicated,but the message sinks without trace.  I can't work out
whether I need to configure exim4, courier, or mutt to overcome the problem.

TIA

richard