Forum Discussion
"Outlook data file cannot be accessed" when trying to send from shared mailbox?
ComotoJC, I was able to fix one of my shared email accounts that had the same issues as you describe. I thought I share what worked for me. I compared the shared mailbox that was not working to a second working shared mailbox and noticed that the working mailbox has two data files compared to the one with the broken mailbox. One is the standard OST, and the second is an NST. After reading this post-https://www.systoolsgroup.com/nst/, I determined it must be the issue.
My fix was to remove the broken shared mailbox from Outlook and add it back. It took Office365 thirty plus minutes to sync up and recreate the data files. Once the sync completed, the broken shared mailbox now had the two data files, and I was able to send an email as the shared mailbox account name.
BTW: Outlook did an automatic restart when it completed the synchronization.
Hope this helps.
ComotoJC The one issue that is probably messing you up is the auto-mapping in Office 365. I had to remove all the users from the shared mailbox. I manually entered each user using PowerShell.
Use the cmd -- Add-MailboxPermission "The name of your shared mailbox" -User user1@xxx.com -AccessRights FullAccess -InheritanceType all -AutoMapping $false --
followed by the second command -- Add-RecipientPermission "The name of your shared mailbox" -Trustee user1@xxx.com -AccessRights SendAs -Confirm:$false
You will then have to manually add the mailbox for each user in their Outlook allowing Outlook to sync with Office 365.
If you rely on the automapping to do it all for you it will not work. At least for me.
