Your email password can be changed on both your Plesk account and email account.
1. Changing Password from Plesk
Log onto your Plesk account.
On your Dashboard, click onto 'Mail' on the left-hand side. Then, click on the Email account that you want to change the password for. You will be able to either create your own password, or have one generated for you. Once you are happy with your new password, click 'Apply' at the bottom of the webpage.
2. Changing Password from your Email Account
Log onto your emal account.
On the left-hand side of the webpage, click on the gear symbol. This will take you to the settings page.
Click on the symbol for the 'General' section on the left-hand side. It should look like:
From here, you will be able to change your password to a new one. Once you have entered your new password in the required field, click on 'SAVE' in the top-right corner.