You can change your domain-based email account password from Cpanel simply by following this article.

Before that, you can access your domain-based email from a portal called webmail on Cpanel and the possible URL for the webmail are :

   https://webmail.yourdomain.com

https://www.yourdomain.com:2096

Change Webmail Password from CPanel

Here’s how to change the email account password in cPanel.

1. Sign in to your cPanel account.
2. Go to the Email section and click on Email Accounts.

3. Click on Manage of the domain of which you want to change your email account.

3. The window below appears. Enter the New Password you want to set for your domain email account.

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4. Click on Update Email Settings once you enter your new password. And once you finished these steps, go and change your email password in all your client’s emails to send and receive email.