how to fix the mailbox replication service was unable to connect to the remote server

Chris Parke 20 Reputation points
2024-01-18T19:02:11.2566667+00:00

Receiving the following error when trying to migrate a mailbox from our hybrid server to out exchange online. Error: MrsHttpUnauthorizedException: The Mailbox Replication Service was unable to connect to the remote server using the credentials provided. Please check the credentials and try again. The call to 'https://hybridcom/EWS/mrsproxy.svc' failed. Error details: The HTTP request is unauthorized with client authentication scheme 'Negotiate'. The authentication header received from the server was 'Negotiate,NTLM'.

Microsoft Exchange Hybrid Management
Microsoft Exchange Hybrid Management
Microsoft Exchange: Microsoft messaging and collaboration software.Hybrid Management: Organizing, handling, directing or controlling hybrid deployments.
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  1. Wandi Ding -MSFT 2,865 Reputation points Microsoft Vendor
    2024-01-19T06:35:43.02+00:00

    Hello @Chris Parke

    Welcome to our forum!

    The error message you provided indicates that the Mailbox Replication Service was unable to connect to the remote server using the credentials provided. This issue seems to be related to the credentials that you used for migration endpoint. It may be caused by the wrong password for the migration endpoint on On-Premises end.

    In order to resolve the issue, it is recommended that you try the following steps:

    1.Open Office 365 Exchange Portal – Recipients- Migration – Click on Migration endpoints. Update the Migration Endpoint Password – which has access to On-Prem Mailboxes. Then rerun the migration.

    2.Use the Test-MigrationServerAvailability command to see what messages you get, and then troubleshoot according to the link on the Exchange team blog about solving this issue. You may could refer to "Option 3: Test-MigrationServerAvailability fails with 401 Unauthorized, Access Denied, or Invalid Credentials section.

    3.Please verify that the credentials you are using are correct and have sufficient permissions to perform the migration.


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