Some providers offer you the choice between PHP4 and PHP5. To run scripts under PHP4, scripts should be named ending in .php, for PHP5 you should name them ending (e.g.) in .php5.
To make this work with PHlyMail Personal Edition, just rename these three files in the main directory of PHlyMail:
index.php
config.php
install.php
Choose the extension your provider told you to use for PHP5.

