Warning: require(Net/SMTP.php): failed to open stream: No such file or directory in /sites/aghdrive/var/pear/doc/Net_SMTP/examples/basic.php on line 3

Fatal error: require(): Failed opening required 'Net/SMTP.php' (include_path='.:/usr/local/lib/php') in /sites/aghdrive/var/pear/doc/Net_SMTP/examples/basic.php on line 3