My company’s management is exploring the possible of having our email hosted by a third party instead of being done in house. We are currently on Exchange 5.5 and holding on migrating to Exchange 2007 because of this. Here's my question. My company has about 85 users some of which have access to other people calendars and mailboxes. Can this still be done if email is hosted outside our company? What are the pros and con's of not having an Exchange server in house?