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Error message when you try to migrate users from an on-premises Exchange Server environment to Exchange Online in Office 365: "Unable to connect to the server"

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�You use the New Migration Batch Wizard in the Exchange Admin Center in Office 365 or you use�the E-mail Migration Wizard in Exchange Control Panel in Office 365 pre-upgrade�to try to migrate users from an on-premises Microsoft Exchange Server 2010, Exchange Server 2007, or Exchange Server 2003 environment to Exchange Online. However, you receive the following error message:
Unable to connect to the server. Please check the connection settings you supplied and try again.

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This issue occurs for one or more of the following reasons:
  • The on-premises computer that's running Exchange Server is configured incorrectly to accept external connections from the Simple Exchange Migration engine.
  • The user account that's used to access the on-premises mailbox doesn't have the appropriate permissions level to access the mailbox.
  • Autodiscover is set up incorrectly.
  • The fully qualified domain name (FQDN) or remote procedure call (RPC) proxy address isn't entered correctly in the E-mail Migration Wizard.
  • The on-premises version of Exchange isn't supported by the Email Migration Wizard or the New Migration Batch Wizard.

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To fix this issue, follow these steps.

Note�Migrating users from on-premises Exchange 2003 isn't supported in Office 365.

Step 1: Check Outlook Anywhere or RPC over HTTP settings on the on-premises Exchange server

The New Migration Batch Wizard in the Exchange Admin Center and�the E-mail Migration Wizard in Exchange Control Panel use Outlook Anywhere or RPC over HTTP to connect to on-premises mailboxes to migrate data. To confirm whether Outlook Anywhere settings are correct, go to one of the following Microsoft websites:Outlook Anywhere requires that Internet Information Services (IIS) websites for Exchange Server use Basic authentication. For more info about how to set up Basic authentication for Outlook Anywhere, go to one of the following Microsoft websites:Make sure that Secure Sockets Layer (SSL) is set up for Outlook Anywhere. For more info, go to one of the following Microsoft websites:If you're using the Staged Migration option or the Cutover Migration option in the Exchange Admin Center to migrate mail data from Exchange Server 2013, Outlook Anywhere must be set up correctly. For more info, go to the following Microsoft website:If you're trying to migrate users by using the Remote Move option in the Exchange Admin Center, the Mailbox Replication Service Proxy must be enabled on the Exchange servers. For more info, go to one of the following Microsoft websites:

Step 2: Confirm that the public certificate is valid for Outlook Anywhere

  1. Browse to the Outlook Web App page of your company website.�
  2. In the Website Identification prompt, click View certificates.

  3. In the Certificate dialog box, make sure that the date of the certificate is valid and that the certificate is from a trusted authority.

  4. Click the Details tab.
  5. In the Subject Alternate Name field, make sure that the FQDN for the Outlook Anywhere address of your on-premises Exchange Server environment is listed.

Step 3: Use Remote Connectivity Analyzer to perform an Outlook Anywhere test

The E-mail Migration Wizard uses Autodiscover to connect to Exchange Server 2007 and Exchange Server 2010 environments and to download the Outlook Anywhere settings. When the migration engine receives the correct response for the Autodiscover service, it uses Outlook Anywhere to connect to the on-premises mailbox.

To troubleshoot connectivity failures to the on-premises Exchange Server environment, follow these steps:
  1. In a web browser, browse to
  2. Under�Microsoft Office Outlook Connectivity Tests, do one of the following:
    • If you're migrating users from Exchange Server 2013, Exchange Server 2010, or Exchange Server 2007, click Outlook Autodiscover.
    • If you're migrating users from Exchange Server 2003, click Outlook Anywhere (RPC over HTTP).
  3. Complete all the required fields on the form, and then click Perform Test.
  4. When the test is finished, confirm that it was successful. If the test wasn't successful, use the info that's provided to resolve the connectivity issue.
  5. Use the super user credentials to confirm through Outlook that you can connect to the on-premises Exchange server of the user whom you're trying to migrate.
  6. If you continue to experience the same errors by using those credentials, repeat the test by using the credentials of the user who is set to be migrated.

Step 4: Validate the permissions that are required to migrate users from the on-premises Exchange Server environment

Exchange Admin Center-based migrations and Exchange Control Panel-based migrations of on-premises mailbox data require that an account that has full access to the on-premises environment be used when the migration is performed. Use the following resources to confirm that your on-premises environment is set up correctly. Be aware that the migration service account will require the Receive As permission to the mailbox database or the Full Access permission to the individual mailbox that has to be migrated.�

For more info about how to provide valid permissions to the migration accounts, see the following Microsoft resources:
For Exchange Server 2003
268754 How to assign users or groups full access to other user mailboxes
821897 How to assign service account access to all mailboxes in Exchange Server 2003
For Exchange Server 2007
For Exchange Server 2010

Step 5: Use the Test-MigrationServerAvailability cmdlet to obtain additional details about the error

To test the connection to the remote server by using Windows PowerShell in Exchange Online, run the Test-MigrationServerAvailability cmdlet.

The following is an example of how to use this command to test access to a server that's running Exchange Server 2007 and on which Autodiscover is set up:
$PSCredentials = Get-Credential
Test-MigrationServerAvailability -Autodiscover �EmailAddress -Credentials $PSCredentials -Verbose 

The following is an example of how to use this command to test the connection to a server that's running Exchange Server 2003 or on which Exchange Autodiscover isn't set up:
$PSCredentials = Get-Credential

Test-MigrationServerAvailability -Exchange -ExchangeServer -Credentials $PSCredentials -RPCProxyServer -Authentication NTLM -Verbose

The results from running this cmdlet should give you more info about exactly where the connection may be failing.

Still need help? Go to the Office 365 Community website.

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Keywords: o365, o365a, o365e, o365p, o365022013, after, upgrade, o365062011, pre-upgrade, o365m, kbgraphic, kbgraphxlink, KB2389390

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Article Info
Article ID : 2389390
Revision : 46
Created on : 9/12/2013
Published on : 9/12/2013
Exists online : False
Views : 83