By Pressing Option 1 (Check Mail)
The Username and Password window will appear (As shown in picture) .
Type your mail address ( as typed in Picture )
Write your Username inplace of UR-USER-NAME (e.g. usman)
and your departmental domain inplace of UR-DOMAIN (e.g. itc)
If your username and password is right then the following page will appear.
Type your new password and then Retype that password.
After typing the new password Press Change Password Button to change your password.
If you don't want to change passowrd then click on return .