@Samar said in mailparse extension:

install uvdesk.

you must compile PHP with mailparse support by using the --enable-mailparse configure option.

Windows users will enable php_mailparse.dll inside of php.ini in order to use these functions. Windows binaries (DLL files) for this PECL extension are available from the PECL website.
You can read Installation Of UVdesk
https://www.uvdesk.com/en/blog/installation-open-source-helpdesk-uvdesk/