We are running ListServ on Solaris machine.  Yesterdy when a user (who is
an editor) posted a reply on a 'send=editor, hold' list, the post was
forwarded to the first editor with the following message:

The enclosed message, found in the XXX mailbox and shown under the spool
ID 31925 in the  system log, has been identified as  a possible delivery
error notice for  the following reason:  "Sender:", "From:" or
"Reply-To:" field pointing to the list has been found in mail body.

the sender used the same email address to XXX list many times before
without problems.  All the other members replied to other's post
(including 'To: [log in to unmask]) too.  Would any one please
shed light on this message?  Thanks!

Shinn