How to make Mail::factory PHP5 compliant?

I have PHP5 installed and my Mail::factory is erroring out saying it can't find the "Mail" class.

How can I make the script PHP5 compliant? I had to install PHP4 just to make it work. Any help would be greatly appreciated.

 

I guess you mean the Pear-Package Mail (->http://pear.php.net/manual/en/package.mail.mail.php)

You should just install it on the console with
pear install Mail

 

So I'm confused, why with PHP4 this is automatically included and not with PHP5?

BTW, my setup was the Perfect Setup /w ISPConfig on Ubuntu Edgy.