Pear won't effect the deliver-ability of an email. Do you have PEAR installed on your php server? Usually you can leave the path to pear blank and it will be defaulted when PEAR is installed.
Create a blank page with this code on it:
Make sure that pear is installed properly.
A blank page generally means an error without errors being displayed. If you add this code to the top of the page then it will give you more information about errors that occur: