Check the application's current dependency list and identify the runtime used by its mail-import process. A browser request, cron job and background worker may use different PHP executables. Keep a sample message that contains no confidential customer information for testing.

1. In cPanel, search for Select PHP Version and open the CloudLinux tool. It is commonly listed under Software. Select the intended domain if your installation displays a domain selector.
2. Check the active PHP version and which websites the selector change will affect. cPanel may also offer MultiPHP Manager and MultiPHP INI Editor. These tools manage a different PHP configuration path. Identify whether the domain uses CloudLinux Alt-PHP or a native EasyApache PHP handler before editing.
3. Open Extensions for the active PHP version. Locate mbstring and mailparse. Mailparse requires mbstring to be enabled and loaded before Mailparse in this runtime.
4. Enable the required extensions and save if requested. The selector offers extensions installed by the server administrator. If both are selected but Mailparse cannot load, ask support to check the installed packages and extension load order; selecting checkboxes does not configure that order by itself.
5. Run the application's dependency check and import a small test message with a harmless attachment. Verify the scheduled importer separately if it runs through cron.

Confirm that the application reports the extension available and correctly separates the message sender, subject, body and attachment. Check character encoding with a representative multilingual message if your helpdesk handles multiple languages.

If the browser reports success but cron still fails, compare the cron PHP path and loaded extensions, including mbstring. Ask support to check that mbstring loads before Mailparse in the failing runtime. If an extension is unavailable for the selected version, ask for the supported combination. Do not paste real customer messages or mailbox credentials into a public diagnostic page.

• Changing PHP versions, extensions and application limits
• Creating and monitoring cron jobs and scheduled tasks
• Creating a business mailbox and connecting your email apps
• Enabling the GD image extension with CloudLinux in cPanel
• Enabling ionCube Loader with CloudLinux in cPanel

• CloudLinux: PHP Selector for users
• CloudLinux: PHP Selector and control panel integration
• PHP: Mailparse
• PHP: Mailparse installation and mbstring dependency