XOAuth2 returns "unauthorized_client"

[maggialejandro]

I want to send an email from the Google account currently logged, so I'm trying to send mail through XOAuth2 option.

I'm setting these parameters:

XOAuth2: {
  user: <application's email account which I login using oauth> (not the account i'm trying to send the mail),
  clientId: <Client ID for web application>,
  clientSecret: <Client secret from web application>,
  refreshToken: <the one I get in OAuth 2.0 Playground>
}

Also I'm using hello.js for authenticating with OAuth2.

Is this configuration correct?
Thanks in advance!

[andris9]

unauthorized_client might happen when clientId and clientSecret do not match

[maggialejandro]

It says 'Username and Password not accepted. [...]"

I use clientId, clientSecret and user (email address) from console.developers.google.com.

XOAuth2 parameters change depending on who is sending the email or those parameters are from Google App owner?

I already added https://mail.google.com/ scope on Google's OAuth 2.0 Playground

[maggialejandro]

Any chance to send an email using this library, without requiring the user to type his password every time?

[AnupKumarPanwar]

Check the following things :-

1. The Redirect URI is set to "https://developers.google.com/oauthplayground" in your Google Developer Console Project.
2. Enter the values of "pass" parameters too. Something like
   XOAuth2: { user: "username@gmail.com", // Your gmail address. pass: "XXXXXXXXXXXXXXX", // Not @developer.gserviceaccount.com clientId: "XXXXXXXXXXXXX", clientSecret: "XXXXXXXXXXXXX", refreshToken: "XXXXXXXXXXXXX" }

Check This Example

[AdamCraven]

For anyone having "unauthorized_client" issues whilst the following apply:

• Using a service account
• Have a google suite account attached
• Have followed all the 2 leg instructions at: https://nodemailer.com/smtp/oauth2/#oauth-2lo

I finally solved it following the documentation here: https://developers.google.com/identity/protocols/OAuth2ServiceAccount#delegatingauthority

In essence going to
https://admin.google.com/**yourgsuitedomain.com**/ManageOauthClients
Adding a client id (from service account) and scope: https://mail.google.com/ (final slash important)

Emails started working after that.