Yes: because the mail system at mainstreet.opm.gov is NOT compliant
with the RFCs.  It should have sent it to [log in to unmask]
 
Feel free to forward that bounce to that Marist address indicating that
your recent distribution bounced and that the list-owner needs
to delete the offending userid from the subscriber list.
 
If they can't figure out, someone here will be glad to help
them.
 
/Pete Weiss,
 Penn State