Set up a staged migration of Exchange Server 2003 and Exchange 2007 to Office 365


Aplica-se a: Office 365

Última modificação do tópico: 2014-10-14

As part of the process of deploying Office 365, you can choose to migrate the contents of user mailboxes from your source email system to Office 365 mailboxes. We recommend that you use staged migration when:

  • Your source email system is Microsoft Exchange Server 2003 or Microsoft Exchange Server 2007.

  • You have more than 50 mailboxes.


Setting up email is a required step in a setup path for Office 365. For more information, see Streamline your deployment of Office 365.

Here are a few items to be aware of:

  • Accounts must be synchronized between your on-premises Active Directory domain and Office 365 by using Azure Active Directory sync for a staged migration to work.

  • The primary domain name used for your on-premises Exchange organization must be an accepted domain in your Office 365 organization.

  • You can migrate user mailboxes and resource mailboxes only. Other recipient types, such as distribution groups, contacts, and mail-enabled users are migrated to Office 365 through the process of directory synchronization.

  • Out of Office messages aren't migrated with user mailboxes. If a user turns on the Out of Office feature before the migration, the feature will remain enabled on the migrated mailbox but the Out of Office message will be blank. People who send messages to the mailbox won't receive an Out of Office notification. To allow Out of Office notifications to be sent, the user needs to re-create his or her Out of Office message after his or her mailbox has been migrated.

  • If you limited the connections to your source email system, it’s a good idea to increase them to improve migration performance. Common connection limits include client/server total connections, per-user connections, and IP address connections on either the server or the firewall. If you haven’t limited these connections, you can skip this task.

To migrate email, you need access to the user mailboxes in your source email system.

After the mailboxes are migrated and the on-premises accounts are converted to mail-enabled accounts, Outlook automatically connects to Office 365.

To finish a staged email migration successfully, it’s a good idea to be comfortable doing these tasks:

  • You configure or verify that directory synchronization is working.

  • You configure or verify that Outlook Anywhere is working.

  • You create one or more lists of mailboxes to migrate in Excel.

  • You use step-by-step wizards in Office 365 to configure and start the migration process.

  • You add and/or change your organization's DNS records, such as the Autodiscover and MX records. We provide instructions on how to do this for many DNS providers.

  • You mail-enable on-premises mailboxes.

If you’re comfortable with what’s involved in migration, you’re ready to get started.


Get started

When you’re ready to start, go to what will happen during the migration.

Here are some options for setting up your staged migration to Office 365.


Method Description More information

Start using new mailboxes and don’t migrate existing email

This is the fastest and easiest way to get started with email in Office 365. Users can start sending and receiving emails in their new Office 365 mailboxes, which were automatically created when you created user accounts licensed for Exchange Online.

Use a third-party email migration tool

Migration tools can help speed up and simplify email migration. You can find a list of tools in the Office 365 Marketplace.

Use Outlook to move information between email accounts

This is a three-step process that is performed one mailbox at a time. Here are the steps:

  1. Add the source email account as an account in a desktop version of Outlook.

  2. Export all of the information from that account to an Outlook data file (.pst file).

  3. Import that Outlook Data File into an Office 365 account.

You can do this process yourself for each user mailbox, but this can take a long time if you have a lot of mailboxes. Another option is to teach users how to do this themselves. To learn how, see Use Outlook to move information between email accounts.

Hire a partner to help migrate your email

You can find a list of partners in the Office 365 Marketplace.