A new subscriber to my list is at a site that recently
established its connectivity to the Internet.
    It took them awhile to get their MX record definition correct,
but that problem has been resolved.  Now there are two new problems.
 
  1) 550 Error Message
     What needs to be done to correct this scenario?  Sample text
     follows:
     xxx.xxx.edu unable to deliver following mail to recipient(s):
        <[log in to unmask]>
        <[log in to unmask]>
     xxx.xxx.edu received negative reply:
     550 SENDER IS NOT REGISTERED AND AUTOREGISTRATION IS OFF
 
  2) The subscriber's EMAIL appears to contain an expansion of
     nickname's text within the body of his messages.  When
     posting to the list, the "nickname expansion" doesn't present
     any problems; however, the extraneous data precludes him from
     sending commands to the LISTSERV.
     He is using PROFS.  Are there PROFS options to suppress the
     "nicknames expansion"?
 
     Thanks!
     James Bradshaw
     Clemson University