The correct  solution is  to fix  sendmail so it  doesn't do  DNS queries
until it  actually needs  the info  for something,  or to  get rid  of it
altogether.  Various incorrect  solutions could  include making  your own
copy of lsv_amin.c with the 'in'  prefix changed to 'aa' or whatever, and
using  this for  your  important  lists. Whether  it  actually gives  you
precedence  varies  from  one  unix  to another,  and  it  clearly  won't
interrupt the job  in progress (which at  30 sec per RCPT  TO: could take
hours to run) to run your new request.
 
  Eric