Yesterday morning we switched from UTDALVM1 as our primary nodename to
  UTDALLAS.  All has apparently gone well with the exception that during
  the first 35 minutes of LISTSERV operation (10:55 CST - 11:30 CST)
  I had the MAILER variable in LOCAL SYSVARS incorrectly left pointing
  to UTDALVM1.  This caused our MAILER to reject and return a fair bit
  of list mail (since it thought it was being asked to deliver remote
  mail from a remote user) -- most noticeably on SAS-L.
 
It seems like everything is flying just fine now, tho.  If you do see
  rejections with UTDALVM1 or UTDALLAS involved after 11:30 CST yesterday,
  please let me know about it.
 
Sorry for the trouble,
                       David