Ideas for Mail and Calendaring for 50,000 Users

[Jason Joines]

  We just got a new CIO at the university where I work.  One thing he is 
about to do is get rid of all the different mail systems and have one 
big combined system for all employees and students.  That'll be about 
50,000 users.

  At the moment the predominant faculty/staff mail system is Lotus 
Domino on windows 2k and the predominant system for students is Sun 
Internet Mail Server on Solaris.  He intends to replace these with ms 
exchange on windows 2k.  There is a small chance he will listen to 
suggestions to consider non-exchange options.

  Any suggestions?

Thanks,

Jason Joines
Open Source = Open Mind
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