Deleted SCP, and powered off old Exchange 2010 serve, now it is getting this error when migrating

Namless Shelter 231 Reputation points

Hi there,

Please help.

We were running hybrid Environment with our Emails (Exchange 2010, Exchange 2016 and Office365)/....I am planning to decommission the old server 2010 Exchange server. It has been a few weeks after I deleted the SCP pointing to the old server 2010, and powered off the old exchange 2010 server.... it left with only running hybrid of exchange 2016 and Office 365.

Now, when I was trying to migrate an old mailbox from server 2016 database to office 365 online exchange account, I click migrate to the online exchange, I got this error: The connection to the server '' could not be completed.

Would you think it is related to the old exchange server got powered off? Or somehow When I click on Migration Endpoint under Migration Tab, the there is no Endpoint any more...I remember there should be one entry here...


Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
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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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3 answers

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  1. Andy David - MVP 145.5K Reputation points MVP

    Did you re-run the Hybrid Wizard and point it to the 2016 server?
    Are the firewall rules updated to reflect the new server?

  2. Andy David - MVP 145.5K Reputation points MVP

    If the Exchange endpoint has changed from the 2010 to the 2016 server, then yes you need to rerun the Wizard and ensure that 2016 server can communicate with the Microsoft endpoint on port 443 and 25.

  3. Joyce Shen - MSFT 16,651 Reputation points

    Hi @Namless Shelter

    Yes, we need to rerun HCW, after rerunning HCW on Exchange 2016 server, it will switch hybrid end point from Exchange 2010 to Exchange 2016. So, you can uninstall Exchange 2010 sever after moving mailboxes from Exchange 2010 to Exchange 2016. (You can try to shutdown Exchange 2010 and observe a period of time before uninstall it.)

    Make sure you have finished the below steps before uninstalling the server: Modify or Remove Exchange 2010 (applied to EX2016 as well)

    1. All Client Access server FQDNs are pointing to Exchange 2016.
    2. All mail flow connectors are pointing to Exchange 2016.
    3. All user and arbitration mailboxes have been moved to Exchange 2016.
    4. If you were using public folders, make sure the public folders databases have been migrated to Exchange 2016.
    5. Any Exchange 2010 CAS arrays you have configured must be removed.
    6. Make a list of applications that may be using Exchange 2010 and then make sure to configure these applications to start using Exchange 2016 if necessary.

    You could check the step-by-step guide in this link as well: Hybrid Exchange 2010 To Hybrid Exchange 2016 - Part Two
    Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

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