Location under cPanelcPanel >> Email - Email Accounts
A secure password is one that contains no dictionary words and includes upper and lower-case letters, numbers, and symbols.
To change the password:
Click Change Password next to the appropriate email account.
Type your new password into the Password box.
Confirm your new password in the Password (again) box.
You can click the Password Generator link to have a strong password generated for you.
Click Change Password to store the new password.
If you do not wish to change the password, click cancel.