About E-Mail Migration
Microsoft Online Services provides tools to help you migrate your e-mail environment to Microsoft Exchange Online. Using the Microsoft Online Services Migration Tools, Microsoft Online Services supports migrations from:
On-premises Microsoft Exchange Server mailboxes
POP3 and IMAP4 mailboxes
When migrating from local Exchange Server mailboxes to Exchange Online, you can establish e-mail and directory coexistence between your local environment and Microsoft Online Services, and perform a migration over time. Migration of your on-premises Exchange Server mailboxes includes all mailbox items, calendar items, tasks, and contacts.
When migrating from POP3 and IMAP mailboxes, you can use the Microsoft Online Services Migration Tools to copy the contents of the POP3 or IMAP mailboxes to Exchange Online mailboxes.
Migrate Exchange Mailbox Content
Migrate POP3 and IMAP4 Mailbox Content
Microsoft Business Productivity Online Standard Suite
Microsoft Online; BPOSHELP