MRS Proxy Error ‘The connection to the server could not be completed’

KB ID 0001358

Problem

When attempting a cross forest mailbox migration, When specifying the ‘Remote MRS Proxy Server address’ you get the following error;

error

the connection to the server ‘server-fqdn‘ could not be completed

Solution

Note: For Office 365 Environments see below.

This tripped me up for quite a while, (it kept saying access denied). I’d tested this previously and everything was working. Note: If you have never had it working, ensure that the name you are using is resolvable in DNS and it’s the name on the certificate of the MRS Proxy server, (or at least a subject alternative name) See this link for how to set it up properly.

Assuming, (like me) everything is OK and the MRS proxy service is running etc, then I found the root cause of my problem by running;

[box]Get-MigrationEndpoint | fl[/box]

I saw the problem straight away, it was using ‘cached credentials for an admin user who had changed their password, now all I had to do was work out how to replace the credentials!

Within the the Exchange admin center > Recipients > Migration > {Ellipsis} > ‘Migration Endpoints’.

Update.

Enter the new (correct credentials)  > Save > Save.

Now retry your ‘batch’ migration.

Office 365 Migration Endpoint Error

If you get the same error when attempting to setup a Migration Endpoint in Office 365;

Then simply skip setting up the endpoint, and perform a batch migration, the system will then connect to the MRS proxy service and work.

Related Articles, References, Credits, or External Links

NA

26 thoughts on “MRS Proxy Error ‘The connection to the server could not be completed’

  1. THANK YOU!!!! I am so happy I found this before getting a little crazy. I was having thoughts of redoing the hybrid configuration – so glad you wrote this. Thank you!

    • I tried to reinstall the hybrid configuration wizard. Good thing I saw this as well before I created the endpoint

  2. Thanks! for me the administrator associated with the endpoint did it, i run an excchange 2010 hybrid.

  3. Thank you so much! I had TWO cases with MS and neither of them checked this. You have save me so much trouble!
    Thank you so much!

  4. I am glad I did not spend too much time to find your posting. It worked. Appreciate your sharing!

  5. Found this super helpful when an admin password was changed mid day and caused Hybrid Office 365 migration to come to a halt – SUPER THANKS!!

  6. Hi, great article.
    This service account what role or what rights does this service account need in order to do the migration ?

  7. I also needed to enable Basic Auth on the EWS virtual directory before my on-premises MRS proxy could be used by O365…

  8. Same error Exchange 2016, unfortunately didn’t resolve my issue. Creds were mine, re-entered, same error.

  9. THANK YOU! I fixed the error… a few hours ago I changed a passwd from a Domain Admin, and that was the cause! I made a new user account for this migration setting only!

  10. This simply resolve the “Remote MRS Proxy Server” error displaying “The connection to the Server “mail.xyz.abc.uk” could not be completed” that was coming up during the hybrid migration exercise to Office 365.

Leave a Reply

Your email address will not be published. Required fields are marked *