Error handling clarification

I am a bit confused by the error handling in PEAR; specifically, how does PEAR's error handling relate to PHP's internal error handling? For instance, using Mail_mime: (in php.ini) error_reporting = E_ALL & ~E_NOTICE (in script) PEAR::setErrorHandling(PEAR_ERROR_PRINT, "Mailer error: %s<br />\n"); When I (on purpose) remove a parameter needed for the send() method, I see an error on the page, but it looks to be a PHP generated error, not PEAR: Warning: Missing argument 3 for send() in C:\development\php-4.3.4\pear\Mail\smtp.php on line 127 I was expecting to see Mailer error: Missing argument 3 for send(). So I thought maybe because I had PHP set to display all errors, it was overriding PEAR, so I changed the entry in my php.ini file to: error_reporting = E_ERROR And now no error shows up at all, even with the intentionally bad method call. Any clarification on PEAR vs. PHP error handling would be appreciated.