Topic Last Modified: 2014-02-27
Summary: Describes planning options for migrating Exchange, Hosted, third party, and IMAP email to Office 365.
Email migration is the process of moving your existing mailbox content to Office 365 and Exchange Online. Migration can occur as quickly or as slowly as your organization wants. Small organizations might be able to migrate mailbox content to Exchange Online overnight or over a weekend. Larger or more complex organizations typically prefer to establish a hybrid email and directory configuration for a longer period of time and perform a controlled migration in logical stages. The ultimate goal of the migration process is to have a unified migration experience for end users with minimal impact to their daily routines.
Office 365 lets you do the following types of mailbox migrations:
Exchange Server mailbox migrations
Hosted Exchange mailbox migrations
IMAP4 mailbox migrations
Third-party messaging system migrations