mistakenly merged users

Question

mistakenly merged users

Carol Holmes 0

I was trying to add a new user and remove an old one but was having difficulty. So I edited the old user and entered the name and email for the new one. Now the old one still shows in multiple references and for outlook, the new user is now seeing all the emails, calendar entries, etc that the old user had. How can I fix this? I am NOT an IT person so anything to technical will be "over my head"

Carol Holmes 0 Reputation points

2026-02-10T17:24:13.2433333+00:00

I don't have an IT department. I am the business owner and the only person who can try to fix this
VEMULA SRISAI 14,065 Reputation points Microsoft External Staff Moderator

2026-02-11T02:49:04.6066667+00:00

Hello Carol Holmes,

this happened because the old user’s account was renamed, so Microsoft 365 still thinks it’s the same person and kept all their emails and calendar data. Please go to Microsoft 365 admin → Users → Active users, open that account, and restore the old user’s original name and email. Next, create a new user properly for the new person so they get a clean mailbox. Ask the new user to sign out and back into Outlook so it refreshes. After this, both users will be completely separate again

1 answer

Your answer

Carol Holmes 0 Reputation points

2026-02-10T17:24:13.2433333+00:00

I don't have an IT department. I am the business owner and the only person who can try to fix this
VEMULA SRISAI 14,065 Reputation points Microsoft External Staff Moderator

2026-02-11T02:49:04.6066667+00:00

Hello Carol Holmes,

this happened because the old user’s account was renamed, so Microsoft 365 still thinks it’s the same person and kept all their emails and calendar data. Please go to Microsoft 365 admin → Users → Active users, open that account, and restore the old user’s original name and email. Next, create a new user properly for the new person so they get a clean mailbox. Ask the new user to sign out and back into Outlook so it refreshes. After this, both users will be completely separate again

Answer 1

To resolve the issue of mistakenly merging users in Outlook, you can follow these steps:

Remove the New User's Access to the Old User's Mailbox: You need to ensure that the new user does not have access to the old user's emails and calendar entries. This can typically be done through the admin center by managing mailbox permissions.
Create a New User Profile: If the new user is seeing the old user's information, it may help to create a new Outlook profile for them. This can be done by going to Control Panel > Mail > Show Profiles, and then adding a new profile.
Delete the Old User: If the old user is no longer needed, you can remove them from the system. Ensure that you have backed up any necessary data before doing this.
Check Email Aliases: If the old user’s email address is still being used as an alias for the new user, you will need to remove that alias. You can do this through the admin center by selecting the user and managing their email aliases.
Consult IT Support: Since you mentioned that you are not an IT person, it might be helpful to reach out to your IT department or a knowledgeable colleague for assistance with these steps, especially if you are unsure about modifying user settings or profiles.

These steps should help you separate the users and restore the intended access and functionality.

References: