UserHasNoMailboxAndNoLicenseAssignedError for previously working non-user unlicensed account

Question

Hi,

I've recently encountered an issue where our team's non-user email account no longer has access to a group email.

We had this non-user email set up so that we didn't need to compromise any individual's email credentials to access this group email account, and so that these credentials could be used with a python library (exchangelib) to access and download attachments programmatically.

The error from exchangelib is:

Invalid credentials for https://outlook.office365.com/EWS/Exchange.asmx

When I went tried to log in to the account to see if it required a password reset or something, I got:

UserHasNoMailboxAndNoLicenseAssignedError

Just wanted to confirm if the issue was the lack of licensing, and that Outlook has recently started to enforce a license, even in applications where there is no real user tied to the account and it is just programmatic access to a group email account. We're happy to pay for the license if that's all it takes to get this account back up and running, but would like to avoid paying for it if this isn't the source of the issue.

Thanks in advance.

Answer 1

If you are logging directly to a mailbox, it does require a license, even if you create it as a shared mailbox. You can however access such mailboxes by means of Full access permissions, without needing to license them. For programmatic access, EWS impersonation will work fine.