Two-step verification method has been introduced to increase users’ security while logging into their email accounts.
Users can choose whether they will use a mobile phone equipped with an application called City Network Authenticator that will generate a one-time password (OTP).
Authenticator is a free application available for iOS and Android.
If Two-step verification is activated for your account, then you will see the following authorization window on your WebClient login page. In this step, you have to enter 6 digit code that was sent to your mobile phone or is accessible in the City Network Authenticator app. It depends on what type of Two-step verification did you choose from.
About your 2-step verification status you are informed within Setting menu:
In case that Two-step verification has not been activated yet, you can always enable this feature by clicking the Enable button.