To enable and disable webmail from the plesk panel, follow these steps.
1. Login to Plesk Control Panel.
2. Click the "Domains" shortcut in the navigation panel.
3) Click the required domain name in the list.
4) Click on Mail Accounts > Mail Settings.
3. Select the dropdown menu for Webmail and select the client you want to use
for webmail. Select the client and hit the "OK" button at the bottom right on
the panel.
4.Your webmail is enabled now.
NOTE:-By default when we create an email account in the plesk panel the webmail is enabled
for that email account.
