App-specific password allows you to configure a password that is unique to each third party email application you use. This improves your email account security. 

Enabling App-specific password will mean your current email password will ONLY work with Webmail. 

One App-specific password applies to one email application. If you have more than one email application, a separate App-specific password should be created for each.

Using App-specific password in email application

When modifying server settings, please check whether you're using an App-Specific Password.

If an App-Specific Password is already set up and you still remember it, re-enter it in the password field of the server settings in the email application in question.

If the App-Specific Password has been forgotten, revoke the existing one, create a new one (with a proper label), and enter it in the password field of the server settings in the email application in question.

How to setup the App-specific password: Set up App-specific passwords

How to revoke the App-specific password: Revoke an App-specific password