Increasing the threshold has multiple POSSIBLE implications:
 
1) e-mail loops take longer to stop
 
2) more list traffic when you might not want a
   chatty list i.e., user needs to "process" --
   read, file, discard, act on
 
3) more host processing during prime-time for a list
   that maybe should not use alot of prime-time CPU
 
4) more space dedicated to archives
 
5) more bounces to handle (by owner/postmaster)
 
6) more bandwidth used (somewhere)
 
NB: please note the use of the word POSSIBLE.  Your
    mileage can and will vary.
 
Pete Weiss at Penn State