Outlook IMAP OAuth in Frappe fails with "AUTHENTICATE failed" when fetching emails

Integration
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1

Hi all,

I’m trying to integrate Outlook email (Microsoft 365) into Frappe using OAuth 2.0, but I’m consistently getting an AUTHENTICATE failed error when it tries to connect to IMAP.

Error Traceback:

Traceback with variables (most recent call last):
  File "apps/frappe/frappe/email/oauth.py", line 43, in connect
    self._connect_imap()
      self = <frappe.email.oauth.Oauth object at 0x7637f575c8b0>
  File "apps/frappe/frappe/email/oauth.py", line 71, in _connect_imap
    self._conn.authenticate(self._mechanism, lambda x: self._auth_string)
      self = <frappe.email.oauth.Oauth object at 0x7637f575c8b0>
  File "/usr/lib/python3.10/imaplib.py", line 444, in authenticate
    raise self.error(dat[-1].decode('utf-8', 'replace'))
      self = <imaplib.IMAP4_SSL object at 0x7637f575e590>
      mechanism = 'XOAUTH2'
      authobject = <function Oauth._connect_imap.<locals>.<lambda> at 0x7637f46a3400>
      mech = 'XOAUTH2'
      typ = 'NO'
      dat = [b'AUTHENTICATE failed.']
imaplib.error: AUTHENTICATE failed.

What’s Already Done:

  • Registered app in Azure Portal
  • Added delegated API permissions:
    • IMAP.AccessAsUser.All
    • SMTP.Send
    • offline_access, openid, email, profile
  • Granted admin consent
  • Scopes added and enabled (checked) in Frappe Connected App
  • Microsoft OAuth authorized successfully in Email Account
  • IMAP access enabled via Microsoft 365 Admin Center → Manage email apps
  • IMAP server config:
    • imap-mail.outlook.com
    • Port: 993
    • SSL: Enabled
  • Cleared Token Cache, re-authorized multiple times
  • Using Microsoft 365 (work)

SMTP Server: smtp.office365.com
Port: 587
Use TLS: Yes
Use SSL: No
Authentication Method: OAuth 2.0 (Microsoft Connected App)
Authorization: Done (clicked “Authorize Microsoft Access”)
Password: Not used (OAuth token used instead)

Environment:

  • Frappe Version: `Screenshots:
  • Hosted: AWS EC2
  • Python: 3.11
  • OAuth method: Microsoft (Connected App in Social Login Key)

Screenshots:

e5898907-14d0-4ad9-b8e8-9181f1b86fda
e5898907-14d0-4ad9-b8e8-9181f1b86fda1337×717 68.7 KB

47285e9a-2714-414e-abea-88a275543707
47285e9a-2714-414e-abea-88a2755437071409×815 63.9 KB

Email Account config:
805a15b5-9c88-408e-95ce-267597e40f44
805a15b5-9c88-408e-95ce-267597e40f441600×670 38.8 KB

Looking For:

  • Has anyone successfully integrated Outlook with OAuth in Frappe v15?
  • Any known patches or debug steps to verify token content or connection?

Thanks in advance!