I've noticed that replies written in MS Internet Mail,
that quote messages they are replying to, seem to be sent as delivery
errors to me as listowner. The error message always refers to there being
pointers in the body of the message to some address in the quoted header.

The problem doesn't seem to arise when other e-mail software is used by my
list members to write replies in which they quote a header from another
message.

I don't use MS Internet Mail. Is there a known workaround for those who do?
Is there any other e-mail
software known to cause this kind of problem - which I see is discussed in
the listowners manual?