Reset an Outlook profile after a mailbox migration
At the end Outlook will open a new, clean profile connected to the user's new Exchange Online mailbox, and you will have checked that Autodiscover points to the right place.
What you need before step 1
Applies to: Classic Outlook for Windows (Microsoft 365 Apps, 2024, 2021, 2019, 2016), new Outlook for Windows and Outlook for Mac, as documented by Microsoft
Admin roles you need
- No admin role. The person doing it needs the user's sign-in details and must be signed in to Windows or macOS as that user.
- To read DNS records in the admin center: Domain Name Administrator or Global Administrator (optional)
Licences
- A Microsoft 365 licence that includes Exchange Online for the user
Web portals you will use (nothing to install)
https://testconnectivity.microsoft.com/tests/o365OpenAlso have ready
- The mailbox migration for this user is complete
- Any local PST files the user keeps are noted, so they can be opened in the new profile
8 steps
- 1
Look at the existing profiles (classic Outlook)
Where: Windows PC, Control Panel > Mail (Microsoft Outlook) > Show ProfilesClose Outlook. In Control Panel select Mail (Microsoft Outlook), then Show Profiles, and note the current profile name. Microsoft says the Mail applet cannot be used to add accounts or profiles for Microsoft 365, so create the new profile from Outlook in the next step.
You should see: A list of profiles, usually one called Outlook. - 2
Create a new profile from the profile picker
Where: Windows PC: hold Shift while starting classic Outlook, or press Windows key + R and run Outlook.exe /profilesIn the profile picker select Options. Tick Prompt a profile to be used so Outlook asks at each start. Select New, type a name such as
Outlook-M365and select OK. Enter the user's email address, select Connect, enter the password if prompted, then select OK and Finish.Outlook.exe /profilesYou should see: Outlook opens the new profile and starts downloading the mailbox. - 3
Make the new profile the default
Where: Classic Outlook profile picker (Shift + start Outlook) > OptionsSelect the new profile in the Profile Name list and tick Set as default profile. Clear Prompt a profile to be used once you are happy. Open any old PST files in the new profile if the user needs them.
You should see: Outlook opens the new profile without asking. - 4
Remove the old profile
Where: Classic Outlook > File > Account Settings > Manage Profiles > Show ProfilesSelect the old profile and select Remove. Outlook may warn that this removes offline data. Mail in Exchange Online and data in PST files is not lost, but deletion of the profile is permanent.
You should see: Only the new profile remains in the list. - 5
Reset the account in new Outlook for Windows
Where: New Outlook for Windows > View > View settings > Accounts > Your accountsUnder Email accounts select Manage next to the account, then in Account details select Remove. This deletes offline cached content for that account but not the mailbox. Then select Add Account, enter the email address, continue and sign in.
You should see: The account reappears under Email accounts and the mailbox loads. - 6
Create a new profile in Outlook for Mac
Where: Mac: Finder > Applications > Microsoft Outlook (Control-click) > Show Package Contents > Contents > SharedSupport > Outlook Profile ManagerQuit Outlook. Open Outlook Profile Manager. Select Create a new profile (+) and type a name. Highlight it, open Set the default profile and choose Set as Default. Restart Outlook and add the account when prompted. To delete the old profile later, select it and choose Delete the selected profile (-).
You should see: Outlook starts with the empty new profile, then shows the mailbox after you add the account. - 7
Check the Autodiscover DNS record
Where: PowerShell or Command Prompt on the user's PC (Terminal on a Mac), plus Microsoft 365 admin center > Settings > Domains > your domain > DNS recordsLook up the Autodiscover record for the user's domain and compare the result with the value Microsoft 365 lists on the domain's DNS records page. If the record still points at an old server, Outlook can keep finding the old mailbox.
Resolve-DnsName autodiscover.contoso.com -Type CNAME nslookup -type=CNAME autodiscover.contoso.comYou should see: The CNAME target matches the Autodiscover value shown in the Microsoft 365 admin center. - 8
Check for Autodiscover overrides in the registry
Where: Command Prompt on the user's Windows PC (signed in as the user)Microsoft documents that values under the Outlook AutoDiscover key (for example ExcludeExplicitO365Endpoint, ExcludeHttpsRootDomain, PreferLocalXML) can stop Outlook finding the right settings. List both keys.
16.0covers Outlook 2016 and later. If values exist that nobody can explain, back up the registry and set them to 0, then test again.reg query "HKCU\Software\Microsoft\Office\16.0\Outlook\AutoDiscover" reg query "HKCU\Software\Policies\Microsoft\Office\16.0\Outlook\AutoDiscover"You should see: Either the keys are not found, or they contain only values your organisation set on purpose.
Expert tips
A new profile uses Autodiscover to find the mailbox. If the DNS record or a registry override still points at the old server, the new profile finds the old mailbox too. Check the CNAME against the admin center and the AutoDiscover registry keys first, then rebuild one test profile before touching others.
For remote move batches, Microsoft says completion reconfigures the Outlook profile to point to the new mailbox, so restart Outlook and wait before rebuilding. New profiles are most useful after IMAP, cutover, staged and cross-tenant moves, where Outlook still points at the old system or account.
Tick Prompt a profile to be used while you test, so the user can switch back by picking the old profile. Remove it only when mail, calendar, shared mailboxes and any PST files are working in the new one, because Microsoft says profile deletion is permanent.
A new profile downloads the mailbox again from Exchange Online. On a small office connection, rebuilding everyone at once can saturate the link on day one. Do it in groups, or overnight, and start with users who have smaller mailboxes.
PST files stay on disk when a profile is removed but are not reattached automatically. Note their paths from File > Account Settings > Account Settings > Data Files in the old profile, then open them in the new one.
How to confirm it worked
Outlook opens the new profile, the folder list matches Outlook on the web, and a test message sends and arrives.
The Autodiscover CNAME matches the admin center DNS records page.
Optional: run the Outlook Autodiscover test at
https://testconnectivity.microsoft.com/tests/o365for the user.
How to reverse it
Until you remove the old profile you can switch back: hold Shift when starting classic Outlook and pick the old profile, or set it as default again. Once removed, a classic Outlook profile cannot be restored (Microsoft says profile deletion is permanent), but mailbox data in Exchange Online and PST files are unaffected.
Errors you might see
The Mail applet cannot be used to add accounts or profiles for Microsoft 365Cause: You tried to create the profile from Control Panel > Mail.
Fix: Create the profile from the profile picker: hold Shift while starting Outlook, or run Outlook.exe /profiles.
Outlook keeps connecting to the old mailbox or fails to find settingsCause: Autodiscover registry or policy values under HKCU\Software\Microsoft\Office\16.0\Outlook\AutoDiscover are set incorrectly, or the Autodiscover DNS record still points at the old system.
Fix: Review the registry values (set unexplained ones to 0 after a registry backup) and correct the DNS record.
Deleting your profile removes offline dataCause: The warning shown when removing a profile.
Fix: Continue if the mailbox is in Exchange Online. Data in PST files is not lost; open those files from the new profile.
Questions
Does removing a profile delete email?
No. Microsoft says data in online accounts such as Exchange or Microsoft 365 is not lost, and PST files stay on the computer.
Does new Outlook for Windows use profiles?
You manage accounts in Settings > Accounts instead. Removing and re-adding the account clears its offline cache.
Do I always need a new profile after migration?
Not always. For remote move batches, Microsoft says completing the batch reconfigures the Outlook profile to point to the new mailbox. Create a new profile when Outlook does not switch over.
Official sources
Vendors change menus and requirements. Confirm on the source before you rely on a detail. Last checked 4 Nov 2026.