If you have an existing hosting/email plan and you purchase one of the managed exchange plans, part of the setup process will involve migrating your data from the old server to the new one.
Managed exchange email differs from traditional POP email in that your emails, contacts, calendar and reminders are hosted on the server rather than on your computer. This offers a greater degree of flexibility for working remotely and offers less scope for losing important information if your computer is damaged or stolen.
In terms of your hosting, the managed exchange plans run on a more modern set of servers and can therefore offer more functionality.
To Export your email files and settings:
To Import the data into the managed exchange mailbox:
To create your mailboxes in Mission Control: