Migrating from on-premise Exchange server to Office 365

TedMorey used Ask the Experts™
Hi - we are a small 10 person company. Previously we have been using an on-premise Exchange server to handle our mail. We are now moving to Office 365 and have created the users in the cloud and migrated the mailboxes. I then tried to run the Outlook migration tool on my computer and it says that manual configuration is required - but did not give details of our situation. There WERE details of how to connect a brand new clean copy of Outlook to Office 365 but NOT how disconnect from a on-premise server and then re-connect to Office 365. Does anyone know how to do this? Thanks Ed.
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Hello again - thanks for getting back to me. We have gotten beyond migrating the data from the on-premise to O365 server - that's done and we can see our mailboxes on the O365 if we loging from a browser. The bit we are stuck on is how to configure Outlook to detach itself from our Exchange server and re-attach to the O365 server. There is a tool in the O365 control panel to do this but when we run it we are told that 'manual configuration is required' but there is no mention of what this 'manual configuration' actually is. Cheers Ed.

You will need to create new outlook profiles on your computers for these mailboxes. That is the "manual" configuration. If you have already setup your autodiscover dns record to point to autodiscover.outlook.com then outlook will configure the settings when you create the new profile.  Because it is a new profile it will need to download the email and create a new ost file. You will also need to setup signatures and any rules the users had.

For configuring the outlook in the office365 you have to take care of following things like:

1) System current date.
2) There should be installation of outlook 2007 or outlook 2010.
3) As said by Epohl, if you have already set up your autodiscover dns record to point to autodiscover.outlook.com then outlook will configure the settings when you create the new profile.
4) If you are doing it manually then you should have exchange server name of the office 365.
5) PowerShell 2.0
6) Office 365 administrator account specified must have a mailbox.
7) Office 365 Kiosk mailbox cannot be used as the target mailbox.
8) For giving the credentials of the configration you must provide the login id and the password of office 365.


Hello everyone - thanks for your helpful suggestions and apologies for the delay in getting back to you - the holidays and actually doing the migration got in the way. I am pleased to say that we are now successfully sat on the O365 platform and I thought I'd share the benefit of my experience with everyone.

1. Migrating from on-premise to Exchange is not as simple as POINT, CLICK, GO!

2. Actually moving the data from one Exchange server to the other didn't work for us using the Microsoft tools, instead we went with MigrationWiz which was well worth the investment and allows you to run the migration several times to catch any straggling emails that miss the DNS cutover.

3. It goes without saying that you have to be very accurate with your DNS entries as prescribed my Microsoft, but I was pleasantly surprised by the clear manner in which the required config was laid out in the O365 admin control panel.

4. Keeping your on-premise Exchange server running at the same time as configuring Outlook to use O365 instead doesn't work unless you change the Service Connection Point Registered with Active Directory. If you don't then although you think you've altered the Outlook config, the next time you relaunch Outlook it partially reverts to the old on-premise config and things don't work. I've pasted a bunch of useful info about this at the end of this message. After we'd done this (using method 2) it all worked fine - this was the vital missing piece of information we needed.

5. Make sure that after installing / updating the Office / Lync apps that you carry STEP 3 of the migration process which runs a number of MS installers / config scripts that make O365 happy. If you don't, it isn't when you start trying to do stuff - especially in SharePoint.

6. Overall, although the migration was a bit painful, we are pleased with the result and can't wait to get our CRM Online and InTune installed in the next few weeks. It means we can turn most of our on-premise servers off!!


I have found this on the O365 Community Forum:

·         Your settings revert back to the old server because you have a Service Connection point registered in your Active directory when you install the Exchange server the SCP will contain the address of CAS server in your AD. Outlook is configured normally to look for the SCP in the AD every time the user logs in after restarting. SInce your SCP has the value of the local CAS   server it will overwrite Office 365 server settings. There are two ways you can tackle this problem depending upon the stage of your migration.

Method 1. If you have not completed the migration then setup outlook manually using the KB aticle KB2404385 before you configure the email account manually  add these following registry keys as mentioned

For Outlook 2007:


For Outlook 2010:


the above registry keys will instruct outlook not to look for AD SCP but look for Http redirect method which will work for your case

Method 2: If you have completed your migration and no user connects to the local exchange server then follow the link to hunt for the SCP in your AD and change its value to "autodiscover-s.outlook.com "  so all the new computers will directly go to Office 365.

To find the SCP in your local AD use this article

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