Auth 2.0 Error 400 on Mail account

I've used this technique in the past with success on:

1. 2006 Mac Pro 1,1 running El Capitan (hacked boot.efi)
2. 2011 Macbook Pro 8,2 running High Sierra.
3. 2009 Macbook Pro 5,1 running Catalina (patched).

And am about to try it again on a 2009 Macbook 6,1 running High Sierra. I'll keep you posted.

Bob, after having deleted your Google account (macOS System Preferences, Internet Accounts), add a new account by selecting "Add Other Account…". Then you can configure your Gmail account by entering your gmail email address and the app password that you created by following the solution described in this thread.

Google seems to have made a change in being more struct regarding security. Apple Mail on High Sierra is pretty old and no longer considered as "secure" by Google. Therefore Google started to block logging into your email account with your regular password.

The workaround is, that you generate a password only to be used for the mail application and nowhere else. Also not storing it on your computer! Whole point is to no longer having to use your regular password on for Apple Mail as it potentially can get hacked. You still can use your regular Gmail password from your phone or through Web. Just the now "insecure" Apple Mail app should use this separate app password to isolate potential damage.

this is happening on my brand new Mac Book pro which I bought yesterday - everything is updated. So how can it be because it is old or outdated?

Thank you for the post but ...

Wait for it-- drumroll.............

Of course we all saw this coming--

In Google Security there isn't an 'Apps' tab to select-

There is a "Recent Security" section listing your device activities with dates

"How to Sign in to Google" with a list of things like-

2-Step Verification

Password

Google Prompt

2-Step Verification Phones

Recovery Phone

Recovery Email

"Your Devices"

"Third Party Apps with account access"

"Enhanced Safe Browsing For Your Account"

"Signing In to Other Sites"

"Looking For Something Else?"

So which is it?

I have tried the steps given by The Animaster and all I get is "unable to verify account name or password"

Background: I changed my google Password as I had an unsolicited verification code sent to my phone

Then my email wouldn't work. I got the same message as others have mentioned:

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.

I have deleted the original Gmail account from my MacBookPro (thank fully it is still all there on my iPhone)

I have tried with and without 2 factor identification on my Google account.

I'm just getting the "unable to verify account name or password" error

I am on High Sierra.

I have 2 other Gmail accounts that still seem to be working OK.

I can access the main Gmail account fine via browser, so I have the correct password.

HELP??!?!? Please

This is so frustrating. I am using a MacBook Air 2015 and cannot install gmail onto the mail app. What is the resolution to this? This has never happened and now I cannot get my emails on my laptop... I know the various route for installing email this is not the problem.....

I understand you want to add a Google account to the Mail app. To do that follow these instructions from the Mail User Guide: Add email accounts in Mail on Mac - Apple Support. Select your macOS version from the dropdown menu at the top of that page. To find out the macOS version your Mac is using please read Find out which macOS your Mac is using - Apple Support.

If you continue to get the error then contact Google for assistance: Contact a third-party vendor - Apple Support.

I seem to have fixed my issue: I found this page How to download and install macOS - Apple Support

and have managed to download and install a later version of OS (Catalina) manually which has allowed my Gmail accounts to link to Apple Mail again.

I'm sure they will fall down again soon as Apple say my machine doesn't support Catalina, but it will hopefully give me a few weeks to research a new machine, rather than a rush purchase.

My Word and Excel for Mac no longer work with the new OS, but they are as old as the machine (2013) and I'm being directed to use Microsoft 365, so I'll have to see if I can find a workaround for this now.

Thank you, The Animaster. It has resolved my problem and extended my Macbook's lifespan by a few years. I would like to add some details that could be useful:

• For some reason, the "App Passwords" section did not appear on my "Security" page. I could only access it by searching for 'App Passwords' in the Google Account search field. If your Google account language is not set to English, you must search for the exact string used by Google in your language for this section (e.g., 'Mots de passe des applications' in French).

• After creating the new password: In Apple Mail, as The Animaster mentioned, make sure to select 'Other' when adding the new email account (you'll need to manually enter all Gmail information). Choosing 'Google account' will result in the same error 'You can't sign in to this app because it doesn't comply with Google's OAuth 2.0 policy for keeping apps secure'.

Good luck!

Error 400 in the context of OAuth 2.0 typically indicates a "Bad Request" error. This error message is usually returned when there is an issue with the request sent by the client.

In the context of a Mail account, this error may occur if there is an issue with the authentication process. It's possible that the authentication token has expired, or there is an issue with the client's credentials. It could also be an issue with the API endpoint or the authorization server.

To troubleshoot this issue, you may want to check the following:

1. Check that the authentication token is still valid. If the token has expired, you will need to obtain a new token.
2. Ensure that the client credentials are correct. If the client credentials are incorrect, you will need to obtain the correct credentials.
3. Verify that the API endpoint is correct. If the endpoint is incorrect, you will need to update it drain mansion apk.
4. Check the logs or error messages for more information on the specific issue that caused the error.

If none of these solutions work, you may want to contact the Mail provider's support team for further assistance.

Yo lo hice así, con doble factor es mas seguro que salga bien. Sobre todo es engorroso por las notificaciones, móvil, y ordenador juntos para los mensajes de texto si es necesario.

• Ahora pasa que no me sale Contraseñas de aplicaciones, ha cambiado.

Entrar en Chrome

1. Preferencias
2. Privacidad y seguridad
3. Seguridad
4. Contraseñas de aplicaciones
5. Seleccionar app (correo)
6. Seleccionar dispositivo (mac)
7. Generar código
8. Copiar código y guardarlo

Luego regrese a las preferencias del sistema y las cuentas de Internet.

Eliges Añadir " OTRA CUENTA

ingrese los detalles con la contraseña copiada

Spoke with Apple tech and solution takes about 15 seconds:

1. System settings
2. Go to: Desktop and Dock
3. Go to: Widgets. (Honest)
4. Go to: Default web browser
5. Change to Google Chrome

That should download all emails and google calendar.

A pesar de haber habilitado la configuración en dos pasos no me aparece "Contraseñas de aplicaciones" sino únicamente "contraseña". Esto me lleva a lo mismo, se abre una ventana para acceder a mi cuenta y poner mi contraseña pero no generar una contraseña. Me puedes ayudar. (te paso captura)

Muchas gracias

Hi Guys, did anyone ever find a solution to adding Gmail back to the Mac Mail? Ive been on the phone to Apple for 1 hour and then Google for another hour. Neither can sort this. All i want to do is have G mail back in to my Mac accounts. What on earth?????

Thanks for all the support offered here. Am I supposed to remove my "not working" gmail account first?

Because when I add account ....it says it already exists.

Many thanks