From time to time, I have communicated with all of our
site's list-owners.  The results of such a communication
usually generates:
 
1) bounces because userid and/or host no longer exist
 
2) additional questions about the specific message (I guess
   that's part of the normal communication process)
 
3) questions as to why I e-mailed the message to them,
   even though it had a preface that indicated it was
   to ALL list-owners hosted by the site (some list-owners
   are unaware that they are list-owners)
 
4) unrelated questions to me just because I "opened" the
   door to communications
 
As you migrate networks and platforms, keep this in mind.
 
/Pete Weiss at Penn State