Im not sure how do do this, i cant find what your talking about, i dont seem to have a php.ini file
Well, gigiburk's solution is only if you are running your web server on Windows operating system. But, if you are running your web server on Linux operating system, you can use an alternative way by using SMTP. I recommend you to use SMTP because, mostly, this usually always works fine, moreover if your mail server is on the different machine with your web server.
Please do search through this forum by entering keyword SMTP, then you will find the solution.
Good luck and cheers!
Best regards,
Masino Sinaga