I had one just this morning from a person who says he can't get LISTSERV
to respond to him <and> when he posts to the list it always says "From:
Unknown Origin".  Looking at his message to me I could see why:  it didn't
have a From: line.  So either his mail program is hosed or his ISP's mailer
is stripping the From: line.

This might be what's causing your user's problem.  BTW the list in question
has ",Confirm" set so this is clearly a problem that has cropped up <since>
he subscribed.  Anyway you should check the headers of mail that he sends
you for any abnormalities.

>I get this from people all the time. I also get messages that they have
>been confirmed (and are getting messages) and then still get this
>failure message. I also am told about signing off (and receiving
>confirmation of getting off) only to keeo receiving messages. When I
>check, they are still there.
>
>I've always put it down to user error. If someone knows differently, I'd
>appreciate knowing about it.