Shared Mailbox keeps prompting for credentials.

Question

Hi,

I have a problem with a shared mailbox that i've created in the exchange online portal.

I can add it in outlook as an extra mailbox but it keeps prompting for my credentials.

If however i create a shared mailbox on our exchange server and then migrate it to the cloud. I have no trouble.

We are not in a real hybrid environment since we are using exchange 2007.

I'm guessing it has something to do with ad not knowing the online shared mailbox but i don't see why that should be a problem. I can add the mailbox so obviously outlook knows it.

I can open the mailbox in the portal so it's not a rights problem?

Answer 1

ok, so i have been able to solve this. It was an autodiscover problem. our exchange autodiscover was already pointing in the right direction but our dns autodiscover wasn't set right yet. we have new issues now (autodiscover not finding anything the first time a user opens outlook. Unless you create a mailuser in exchange) but i will search on this first :) thx anyway for the help.

Answer 2

Hi WesleyDe,

Thanks for your quick response.

Since this issue happened to Exchange online mailboxes, I’d suggest you try the following suggestions to see if this issue can be fixed:

1. Remove the automapping feature and enable it again by refer to:

a) Connect to Exchange Online by using remote PowerShell.

b) Remove Full Access permissions for the user from the mailbox. This removes automapping.

Remove-MailboxPermission -Identity <Mailbox ID1> -User <Mailbox ID2> -AccessRights FullAccess

Note: In this command, <Mailbox ID1> represents the mailbox to which the user is granted permissions, and <Mailbox ID 2> is the mailbox of the user from whom you want to remove full access permissions.

c) Grant full access permissions back to the user for the mailbox, and enable automapping by running the following command: Add-MailboxPermission -Identity <Mailbox ID1> -User <Mailbox ID2>-AccessRights FullAccess -AutoMapping:$True

Note: In this command, <Mailbox ID 1> represents the mailbox to which the user is granted permission and <Mailbox ID 2> is the mailbox of the user to whom you want to add full access permissions.

2. Try creating a new Outlook profile by referring to:

support.microsoft.com/.../829918

3. Run the SaRA toolto diagnose the Outlook client.

If the issue persists after performing the above suggestions, to narrow down the root cause of the issue further, I’d like to confirm some more information:

1. How did you set up the Office 365 account into the Outlook client, via Exchange connection, POP or IMAP?

2. Which version of Outlook client you are using, Outlook 2013 or 2016? I will appreciate that if you can tell me the detailed version. To check it, please click FILE > Office Account.

3. Did this issue happen to all Exchange online users in your organization?

4. Could you please share the email address of the problematic user which prompts for credentials via the private message so that we can check if the related DNS records are set up correctly?

To protect your privacy, I've sent you a private message to collect the above information. Please refer to the following link to read it:

https://community.office365.com/user/conversations

Your time and continued efforts are highly appreciated.

Best regards,

Mouran

Answer 3

Hi, thx for the reply

1. yes that's it & yes i used those steps
2. i assigned the full access permission to the user that wanted to open the mailbox (and it works but only online)
3. the credentials i give are my online credentials
4. no there is no exchange server setup in the outlook client. All our mailboxes etc are in the cloud so our on premise exchange server is not being used atm.
5. yes the "mailbox" refers to the shared mailbox.

Answer 4

Hi WesleyDe,

To better understand the situation, I’d like to confirm some information:

1. What does the “Exchange online portal” you mentioned refer to? Is it Exchange Admin Center (EAC) (https://outlook.office365.com/ecp/)? Did you refer to the following steps to create a shared mailbox?

Login to EAC > recipients > shared, click the Plus sign.

2. How did you add the shared mailbox in Outlook as an extra mailbox? Did you assign the Full Access permission of the shared mailbox to your Office 365 Exchange online account?
3. Regarding “I can add it in Outlook as an extra mailbox but it keeps prompting for my credentials”, does the credential belong to your Office 365 Exchange online account or Exchange server account?
4. By saying “I'm guessing it has something to do with ad not knowing the online shared mailbox but I don't see why that should be a problem”, do you mean that you’ve set up an Exchange server account into the Outlook client?
5. About “I can open the mailbox in the portal”, does the “mailbox” refer to the shared mailbox?

Thanks for your time and efforts.

Best regards,

Mouran