You can use CloudLinux Selector to enable the Mailparse extension in PHP via Plesk.
1. Log in to your Plesk account.
2. In the right-hand sidebar, click on PHP Selector.

3. Click on the Extensions menu.

Note: If the Extensions page shows an error related to the native PHP version, change it to a non-native version first.
4. Checkmark Mailparse. Once enabled, it will display a success message.

The message will read that the module Mailparse is saved.
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