Sometimes you try to log in to your Gmail account in a third-party app, but your request is denied. You may be trying to use SMTP protocol to send Emails through python IDE, or it may be an IoT device trying to log in into a Gmail account, the request might be denied by Google.

This might occur due to the following reasons:

• The app you are using to log in to your Gmail account might not meet the security standards of Google.
• It may be an app that doesn’t use official ways to log in to your email account.

Solution:

There is a feature in Google account “Less secure app access“. This should be enabled in order to login into less secure apps.

To resolve this issue follow the below steps:

Step 1: Go to  https://www.google.com/account/about/

Step 2: Click on “Go to Google Account”.

This will redirect you to your google account page as shown below:

Step 3: Click on the “Security” option on the left menu.

Step 4: Now click on the “Manage Third-party Access” option.

This will redirect you to the Apps with access to your account page as shown below:

Step 5: Now enable the Google Account sign-in prompts as shown below:

At this point, the issue is resolved and you can sign in to third-party apps using a google account.