exchangelib OAUTH authentication NonExistentMailbox error-CodePudding

I have a Python script that is reading Office 365 emails and downloading attachments. I am using exchangelib and trying to switch from Basic Authentication to OAUTH2.

My old script was authenticating without any issues:

from exchangelib import Credentials, Account

username = '[email protected]'
pwd = '123456'
credentials = Credentials(username, pwd)
account = Account(username,
              credentials=credentials, autodiscover=True)

The new one one:

from exchangelib import OAuth2Credentials

username = '[email protected]'
tenant_id = 'TENANT ID'
client_id = 'CLIENT ID'
secret_value = 'CLIENT SECRET'
credentials = OAuth2Credentials(client_id=client_id, client_secret=secret_value, tenant_id=tenant_id)
account = Account(username,
              credentials=credentials, autodiscover=True)

The new script returns an error:

exchangelib.errors.ErrorNonExistentMailbox: The SMTP address has no mailbox associated with it

I have created and registered app in Azure portal. Email/User is added to app.

CodePudding user response：

I tried to reproduce the same in my environment and got the below results:

I created one Azure AD application and added API permissions with admin consent as below:

enter image description here

Now, I ran the same code as you and got the same error as below:

from exchangelib import OAuth2Credentials

username = '[email protected]'
tenant_id = 'TENANT ID'
client_id = 'CLIENT ID'
secret_value = 'CLIENT SECRET'
credentials = OAuth2Credentials(client_id=client_id, client_secret=secret_value, tenant_id=tenant_id)
account = Account(username, credentials=credentials, autodiscover=True)

Response:

enter image description here

To resolve the error, try making few changes in your code like below:

from exchangelib import OAuth2Credentials

username = '[email protected]' ## make sure to give valid address
tenant_id = 'TENANT ID'
client_id = 'CLIENT ID'
secret_value = 'CLIENT SECRET'
version = Version(build=Build(15, 0, 12, 34))
credentials = OAuth2Credentials(client_id=client_id, client_secret=secret_value, tenant_id=tenant_id)

config = Configuration(service_endpoint = 'https://outlook.office365.com/EWS/Exchange.asmx',
                        credentials=credentials,
                        auth_type=OAUTH2 , 
                        version=version)
account = Account(username, credentials=credentials, autodiscover=False, config=config, access_type=IMPERSONATION)
mails = list(account.inbox.filter(is_read=False).only(
        'is_read', 'subject', 'body','text_body','datetime_received',
        'sender','to_recipients','cc_recipients','bcc_recipients',
        'attachments','importance'
    ).order_by('datetime_received')[:1])
print(mails)

Response:

Make sure whether the user has required licenses assigned or not as below:

Go to Azure Active Directory -> Users -> All users -> Select User -> Licenses

enter image description here