I’m having issues with XOAUTH2 authentication for Gmail SMTP. I’ve set up an access token with the https://mail.google.com/ scope, but the server keeps rejecting it. Here’s what I’m seeing:
from smtplib import SMTP
import google_auth_oauthlib.flow
import base64
# Set up OAuth flow
auth_flow = google_auth_oauthlib.flow.InstalledAppFlow.from_client_secrets_file('secret.json', ['https://mail.google.com/'])
credentials = auth_flow.run_local_server(port=4000)
# Prepare auth token
auth_str = f'[email protected]\x01token=Bearer {credentials.token}\x01\x01'
encoded_token = base64.b64encode(auth_str.encode('ascii')).decode('ascii')
# Try to authenticate
with SMTP('smtp.gmail.com', 587) as server:
server.set_debuglevel(2)
server.starttls()
server.ehlo()
server.docmd('AUTH XOAUTH2 ' + encoded_token)
The server responds with an error: eyJzdGF0dXMiOiI0MDAiLCJzY2hlbWVzIjoiQmVhcmVyIiwic2NvcGUiOiJodHRwczovL21haWwuZ29vZ2xlLmNvbS8ifQ==
This decodes to: {"status":"400","schemes":"Bearer","scope":"https://mail.google.com/"}
I’ve tried adding more scopes like gmail.send, gmail.modify, and others, but no luck. Any ideas what I’m doing wrong?
hey there, had similar issues before. make sure ur using the latest google_auth_oauthlib version. also, double-check if ur app is approved in the Google Cloud Console. sometimes it’s just a permissions thing. oh and try refreshing the token before sending - helped me once. good luck!
I’ve encountered similar issues with Gmail SMTP XOAUTH2 authentication. One often overlooked aspect is the client ID and client secret configuration. Ensure these are correctly set up in your ‘secret.json’ file. Additionally, verify that your Google Cloud project has the Gmail API enabled.
Another potential solution is to use the google-auth library instead of google_auth_oauthlib. It provides more robust token management and refresh capabilities. You might also want to check if your Google account has 2-step verification enabled, as this can sometimes interfere with SMTP authentication.
If all else fails, consider using Google’s official Gmail API instead of SMTP. It’s more reliable for sending emails programmatically and avoids many of the authentication pitfalls associated with SMTP.
I’ve dealt with XOAUTH2 authentication issues before, and it can be frustrating. One thing that’s not immediately obvious from your code is whether you’re using a personal Gmail account or a Google Workspace account. If it’s the latter, you might need to ensure SMTP access is enabled for your organization.
Another potential issue could be with the token itself. Instead of using the access token directly, try using the refresh token to generate a new access token just before attempting to authenticate. This ensures you’re always using a fresh token.
Lastly, I’ve found that sometimes the Google OAuth playground can be helpful for troubleshooting. You can use it to generate tokens and test different scopes to see what works. It might give you some insights into what’s going wrong with your current setup.
Hope this helps you get to the bottom of the issue!