Auth 2.0 Error 400 on Mail account

I try to add my account but I got this message


Authorisation 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.

You can let the app developer know that this app doesn't comply with one or more Google validation rules.
Learn more
Request Details
The content in this section has been provided by the app developer. This content has not been reviewed or verified by Google.
If you’re the app developer, make sure that these request details comply with Google policies.
redirect_uri: urn:ietf:wg:oauth:2.0:oob



What's wrong with Apple and Google? Google asks to contact the developer, yes Apple...


It's so frustrating...

Posted on Feb 22, 2023 2:58 AM

Reply
Question marked as Best answer

All advice given here does not solve the problem unfortunately. What is the solution?

Posted on Feb 23, 2023 6:36 PM

184 replies

Oct 4, 2023 11:31 AM in response to edmeyers

edmeyers wrote:

where do i find app passwords.......i'm not seeing it unfortunately but it could be old age


Google Account Help – Sign in with app passwords


You log in to the Google site, and ask Google to create the app password. Then you use it with Mail on the Mac. Note that Google will not generate an app password for you unless you turn on 2-Step Verification.

Oct 21, 2023 6:45 AM in response to The Animaster

Animaster's advice is very helpful, but I needed to make two changes since the OP. First, the App Password did not automatically appear as an option on my Security Page unless I typed App Password in the search field. I also had to take one extra step in between 4 and 5, then it worked. While still in your Google account security page, under Recent Security Activity, open "App password created" and authorize the change. Then you can proceed with step 5 above.

Oct 21, 2023 12:02 PM in response to The Animaster

Brilliant!! It has worked after many days of not being able to.


I think that these security updates that Google makes are for us to update our equipment but not to protect us. I think they are somehow associated with Apple to jointly make profits. They are all the same masters who together manage this entire computer and information business. Some sell programs and computers, others sell our information that they extract from us through their strategies. United for their "business"

Oct 30, 2023 11:40 PM in response to The Animaster

Thank You Animaster. Your solution to get gmail back on Mac Mail worked GREAT! I'm not what I call a computer wizard, but I followed your instructions and it worked. Was ready to buy a new computer as mine is late 2011 but gmail is so painful to use and I have multiple account. But my main one went out. Don't change your password on gmail. That's what caused my main gmail account to go off. Then when I tried to add in mac mail with google it gave me that bs, need Auth 2.0 Error 400. Did't allow me to sync my calendar but just put in under my other gmail account. THANK AGAIN!

Nov 3, 2023 3:54 PM in response to ays177

The Animaster has the solution. Well it's not the easiest thing I've ever done but IT WORKS! I copied it just in case I can't get back to it so here it is. The only down side is your gmail on macmail does't connect to the mac calendar. Here is the Animaster SOLUTION & IT WORKS. Don't let the 2 step verification scare you, it's just what it's called & you only do it once to get it to work. Here it is from the Animaster:

I FOUND THE SOLUTION. 


People have mentioned it here, but with incomplete steps. So here is how to get it done:


1.) KNOW why this is happening in the first place: it's coz Google says your old mac and old mac OS have insufficient security. With that said, you can only update an old mac for about 7-10 years. Then you're SOL. Keep that in mind. Lucky for us old mac users (I'm running a 2011 MBPro with ElCapitan) -- we are still able to add new GMAIL accounts with a workaround. 


2.) As mentioned here, open your GMAIL account preferences by signing into GMAIL by web browser and clicking on your avatar in the upper-right and selecting "Manage your Google Account". Then click on the "Security" tab on the left.


3.) Under "Signing in to Google" ENABLE 2-step verification. This alone will NOT fix it, but it WILL allow you use what Google calls "Less Secure Apps Access". If you notice in your account settings, Google automatically sets this to OFF -- essentially blocking access to any apps that Google dubs 'insufficient security'. Enabling 2-step verification will bring up a third line under "Signing in to Google" that says "App Passwords".


4.) Click on "App Passwords" and this will walk you through generating a password that you can use to manually add a GMAIL account with your old mac. 


5.) Select and copy the generated password, go into Apple Mail preferences and select "other" when adding the new email account. Type in your gmail email address, and use the password you copied earlier, in the password field. 


If this helps, PLEASE hit the kudos button to bring it to the top!


Reply Helpful (116)


Nov 3, 2023 4:03 PM in response to mark2764

FYI the Avatar is your picture on gmail. Didn't know that term. Keep going IT WORKS & it's better than dealing with the gmail format to read your emails especially if you have multiple gmail accounts. I changed my password on my main email account and that's what triggered the my gmail not working on my mac mail account. So don't do that unless you absolutely have to. Again, thanks to people like Animaster for figuring this out and sharing.

Auth 2.0 Error 400 on Mail account

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.