We don't store password, so if you have lost an existing email account's password you will have to setup a new one.
In order to change an email account password follow these steps:
1 - Access your Hosting Panel
Follow instruccions of How to access your Hosting Panel to access your Hosting Panel.
2 - Click on Email accounts
Look for and click on Email accounts icon.
3 - Click on Change Password
Locate your email account in the listing and click on Change Password link.
4 - Define a new password
Just fill in the form with your new password and click on Send button.