Messages still bouncing

Thanks to those of you that replied to my earlier posting.  The problem is
still ongoing with other members of my list.  When they attempt to post,
they get messages that tell them that they are not authorized to post.  The
same message will go through if they try again.  

I have the dist and accept lists set up identically, e.g. everyone who is
authorized to receive messages posted to the list can also post to the list.
Further, some of the "Mail delivery subsystem" error messages I am receiving
are showing that my own address (the one from which I am posting this
message and to which I receive more than 100 messages a day) is invalid.  I
freely admit to being a dope in this area, so if anyone has any suggestions
that will make administration of this list a bit more smooth, I would
appreciate hearing about them.  

Tim Dees
[email protected]