[plug] personal mail configurations

[sol]

More of my mail naivite. ;-)

I've been having some strange mail behaviour regarding mail sent from my 
laptop. My mail header will say things like:

-----Original Message-----
From:   "sol" <sol at chomsky> on behalf of        "sol" <sol at autonomon.net>
Sent:   06 March 2003 03:01

"chomsky" is the name of my laptop. I've also figured out that it's in 
/etc/mailname. However, this seems to be preventing me fromsome mailing 
directly to lists where I am an approved poster. I can't even mail to some 
people. I get the following type of message in /var/mail/sol (i've changed 
the addresses cos it's a generic problem).

This message was created automatically by mail delivery software (Exim).

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

 user at domain.com
    SMTP error from remote mailer after RCPT TO:<user at domain.com>:
    host domain.com : 550 cannot route to sender address <sol at chomsky>

I think the last bit is important. What does "550 cannot route to sender 
address <sol at chomsky>" mean? Shouldn't this be referring to my email address? 
Doesn't this point to my having configured something incorrectly? If so, 
what?

sol