There are really only five main mail platform types used by the organizations that wish to migrate to Exchange Online. These are as follows:
POP e-mail systems
IMAP e-mail systems
Hosted Exchange Server
Gmail or Google Apps
Exchange Server 2003 or 2007
Based on these platforms, we have created several scenarios which are reflective of common customer environments and situations.
Many small businesses currently utilize POP e-mail provided by their domain name or website host. These are the simplest of migrations as the mailbox content is migrated by relying on the PST file import functionality in Outlook. Users simply need to import their existing PST file into the new Exchange Online mailbox.