The only thing you can do is to change/reset your password for your email account via cPanel. cPanel is your hosting control panel and here are some instructions on getting this done:
1. Log into cPanel at http://yourdomain.com/cpanel
2. Click on Email Accounts in the Mail section of cPanel
3. Scroll down until you see a list of your email accounts
4. Click on the Password and Authentication link to right of the email account that you have forgotten your password to. A box will open up below the email address.
5. Enter in a secure password and click the Change Password button
6. Go back to your email program and enter in your new password there and you should then be able to connect to your email account on our server