Not able to get the option to login as a different user in Outlook when signing into Shared Mailbox

I have a workaround that seems to do the job.

If the mailbox has an alias address - eg *** Email address is removed for privacy ***, use that address when setting up the mailbox.

If it doesn't already have an alias address, create a new one and then use that address.

This will still link to the mailbox as normal, but will give you the option to log in as a different user.

When sending email, and as far as the folder list goes, everything will behave normally. The only two side effects I've noticed from this is that the OST file will be named after the alias address (which the user will not even be aware of), and when syncing, the status at the bottom of the outlook window will show that it's syncing the alias address as opposed to the actual address - not the end of the world!

Other than those two things, everything else is the same, but it allows you to switch user accounts when logging in.

EDIT - Bah, Microsoft removed the example email address I put in! The example above was emailaddress at companyname dot onmicrosoft dot com

Hello folks,

Got the same problem here on our workstations (Windows 10 / Office 365).

We converted mailboxes to shared mailboxes and try to reconfigure them on Outlook.

I try many things and the one which seems to work is to delete the 2 following directories :

• %localappdata%/Microsoft/OneAuth
• %localappdata%/Microsoft/IdentityCache

If someone could give a try and confirm.

Please make a backup before deleting ... in case off.

Hello Sam Island,

Good day.

Thank for posting in the community.

We've received your query and you can expect to receive response from one of our community moderator accordingly.

At this point, we appreciate your patience and cooperation. Thank you.

Sincerely,

Community moderator

Hello Sam Island,

Thank you for posting this case in Microsoft Community!

Based on your description: Not able to get the option to login as a different user in Outlook when signing into Shared Mailbox. I would like to cooperate with you working on this case. To clarify this case, this is normal behavior that one normal account set up in Outlook client and then converted into shared mailbox which will not get the option to login as a different user in Outlook. Currently, there are two methods to configure shared mailbox in Outlook client: (1). Automapping with permission assigned. (2). Manually adding to your primary email account profile. You may check this article as reference Open and use a shared mailbox in Outlook.

For your case, it is recommended that you need to remove the old Outlook profile which already converted into shared mailbox in your Outlook and then manually add to your another primary account profile. To create new outlook profile, see Create an Outlook profile - Microsoft Support

To answer your question, when you add a shared mailbox or a delegate mailbox as a secondary mailbox in outlook for windows, since outlook treat the shared mailbox as a normal user mailbox, it will ask you to enter a password. Therefore, you need to enter the primary mailbox password to add the shared mailbox. Let's say you have ******@domain.com and you have full access permission for the shared mailbox ******@domain.com, so that, you can enter the password of ******@domain.com to add the ******@domain.com in Outlook as a secondary mailbox. Here are the steps you may try:

1. Disable automapping on a primary mailbox using PowerShell, you can refer to Remove automapping for a shared mailbox - Outlook | Microsoft Learn
2. After disabling automapping, please open your Outlook>File>Add account>Enter your shared mailbox email address as username and use your primary mailbox password to sign in. Then, check if the shared mailbox added as a separate mailbox in the account settings. To check this, Go to File>Account settings>Account settings>Under Email Tab, check if the shared mailbox listed as additional mailbox.

Hope the above workaround would be helpful. If you need further assistance, please feel free to let me know, I will keep assisting you.

Your understanding and patience will be appreciated.

Thank you!

Community Moderator.

Hi Eleni,

The procedure and steps for adding a shared / delegate mailbox as additional email account in Outlook are correct, but the issue is that when you get a prompt for password it automatically picks a shared mailbox UPN / email address and there is no option to 'Sign in as different user'.

This issue happens only for the users who previously worked on that computer with that account before it was converted to a shared mailbox. if you login to another workstation (you have never before) - it would work and give a prompt for 'Sign in as different user',

However it is not a solution to rebuild a windows user profile for that.