Unable to login into the webmail getting error “Authentication Failed / Unknown or Disabled User! “

Solution :

To check whether you have entered the username and password without any mistakes . If you dono the password kindly follow the below pocedure to reset the ftp password

1] Login to your plesk control panel.
2] Click on subscriptions.
3] Click on control panel of that subscriptions.
4] Click on Mail.
5] Click on the mail id for which you want to reset the password.
6] Change the password [ Give the tough password,which consist of alphanumeric characters ].
7] Click on ok.