When you are switching to a Hosted Exchange Email account, there are four scenarios you may find yourself in:
When you switch from a Workspace Webmail service such as Yahoo!, you need to forward your email to your Hosted Exchange Email account, inform your contacts of your new email, and then import contacts and messages.
You can use the same email address that you had before—and upgrade it to Hosted Exchange Email. You can make this switch without losing any messages and without experiencing any downtime, however, you will need to make sure you give yourself a few hours to do it.
For more information, see Switching From Workspace Email to Hosted Exchange Email without Losing Any Messages.
If you're starting from scratch, follow the instructions in Getting Started With Microsoft Hosted Exchange Email. Then see the information below in Setting Up an Email Client for Hosted Exchange Email.
You can connect to your Hosted Exchange Email account using a desktop, laptop, or mobile device.