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How to update DNS records so all new emails go through Microsoft 365 Exchange Online

This is step 6 out of 8 explaining how to migrate your emails from an IMAP system to Microsoft 365 Exchange Online. To read the earlier steps click on the following links: Step 1 - 3Step 4Step 5.



We are now approaching the final stages of our migration. The next step is to change DNS records on your domain so all new emails go through the new Microsoft 365 Exchange Online. 

This means your current email system will stop working and you won't be able to send or receive emails. Therefore choose a time that doesn't interrupt your working day. You won't lose any emails when we do the switchover. 

1. Go to Microsoft 365 admin center page -

2. Go to Settings and then Domains and next to your domain it should say Incomplete setup.

3. Click on your Domain.

4. Click Continue setup.

DNS switchover - Step 1
DNS switchover - Step 2

Just like when we had to prove to Microsoft you owned your domain and there were options to get Microsoft to automatically add the correct TXT records to your DNs records if it was able to automatically login.

The same steps occur here. Microsoft can update the records as long as you give them permission to do this. This is achieved by logging into IONOS via Microsoft.

Otherwise you will have to add the records manually.

DNS switchover - Step 3

5. Login to your domain hosting account and go to DNS settings.

You will need to delete some existing records before you can add the new ones, so before deleting I always make a note of the existing records in case you need to go back to the original settings.

6. Copy and paste existing settings into Notepad or Word.

7. Delete and add the relevant DNS records as shown below.

MX records

Delete existing record.

Add new MX record.


CNAME records 

Delete existing record.

Add new CNAME record.


TXT records

Add new record.



DNS switchover - Step 4
DNS switchover - Step 5

8. Double check the DNS records have all been entered correctly.

9. Once DNS records have been added go back to Microsoft 365 and click Continue

If successful then great. If not, then leave it for about 30 minutes to 1 hour and try again. It is just a case of having to wait for the DNS records around the world to update. Sometimes it can take 24 hours for all the DNS servers to update so don't worry if it keeps failing. It all depends on the hosting company. Some companies seem to be faster than others.

DNS switchover - Step 7

If successful then you can test your new email system.

10. Open the Outlook webmail like we did at the end of step 5 and send an email. Perhaps send an email to your personal Gmail or Hotmail account. Does it work? If so, send a reply. Does it arrive in the new inbox?

If so, then fantastic. If not then it's usually just a case of having to wait a bit longer for all those DNS records to update.

Once the test emails are working we want to manually check the DNS servers around the world and ensure they are pointing to the correct DNS records. It can take up to 24 hours for all DNS servers around the world to update to the correct values.

11. Go to

12. Enter your domain

13. Change dropdown to MX

14. Click Search

All DNS serves should match the DNS record you added earlier.

DNS switchover - Step 6


When all DNS servers are showing correct values then we can do the final stage migration in Migration Wiz. This will migrate emails younger than 30 days into Microsoft 365 Exchange Online. It usually doesn't take very long.

1. Open MigrationWiz

2. Select emails

3. Got to Start and select Full Migration

4. Click Start Migration


DNS switchover - Step 8


With all emails migrated and working properly in Microsoft 365 it is now time to setup the Microsoft Outlook desktop email program on your computer and other devices such as mobile phone and iPads. You don't have to use Outlook desktop program. if you don't want to.  You can just use web based Outlook like we were using earlier. The choice is yours. 

Click the button below for Step 8.

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I usually reply to online enquiries within a few hours so if you haven't had a reply within 24 hours please check your spam box. 

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