WHY THIS GUIDE?
If you’re trying to add a Gmail or Google Workspace account on a Mac running High Sierra (or older), you might have encountered the following error:
ERROR:
Sign in with Google
Authorization Error
Error 400: invalid_request
You can’t sign in to this app because it doesn’t comply with Google’s OAuth 2.0 policy for keeping apps secure.
Google has blocked older macOS versions because they no longer meet their latest security requirements. But luckily, there’s a manual workaround — and this guide walks you through it step-by-step.
STEP 1: ENABLE 2-STEP VERIFICATION AND GENERATE AN APP PASSWORD
1.Log into your Gmail account via a browser.
2.Click on your profile picture in the top-right corner → select “Manage your Google Account”.
3.Go to the “Security” tab on the left-hand menu.
4. Under “Signing in to Google”:
•Enable 2-Step Verification (if not already enabled).
5.Once enabled, you’ll see a new option called “App passwords”.
6.Open the App Passwords section and generate a new password for “Mail” or “Calendar”.
•Copy the password — you’ll need it during setup.
STEP 2: SET UP GMAIL MANUALLY IN APPLE MAIL
1. Go to Mail > Preferences > Accounts > Add Account.
2. Choose “Other Mail Account…”.
3.Enter your name, Gmail address, and the app-specific password you generated.
4.Click “Sign in” — it won’t connect automatically, so continue with manual settings:
• Incoming Mail Server (IMAP): imap.gmail.com
•Port: 993
•Use SSL: Yes
• Outgoing Mail Server (SMTP): smtp.gmail.com
•Port: 465 (SSL) or 587 (TLS)
•Use SSL: Yes
•Requires Authentication: Yes
5.Confirm and finish the setup. Mail should now work.
STEP 3: SET UP GOOGLE CALENDAR VIA CALDAV (MANUAL METHOD)
1. Go to System Preferences > Internet Accounts > Add Other Account.
2. Select CalDAV Account.
3. Choose Account Type: Advanced.
4.Fill out the following:
•Username: your Gmail address
•Password: the app-specific password
• Server address: https://calendar.google.com
• Server path: /calendar/dav/yourmail@gmail.com/user/
(Replace “yourmail@gmail.com” with your actual Gmail address)
• Port: 443
•Use SSL: Yes (check this box)
•Use Kerberos: No (leave unchecked)
5.Click Sign In.
Your Google Calendar should now sync with the Apple Calendar app.
USEFUL LINKS
•Gmail App Password Instructions:
https://discussions.apple.com/thread/254659965?sortBy=rank
•CalDAV Setup Help:
https://discussions.apple.com/thread/254741621?sortBy=rank
NEED HELP?
Call us at +45 40842008 for personalized Mac support today.
Even though Google has restricted direct login from older macOS versions, you can still use your Gmail and Google Calendar with this manual workaround. It just takes an extra step with an app password and manual configuration — but it works!
Good luck!
