You can put those files anywhere you want, but the easiest way would be as a plugin, I guess, if need be, you can write a simple wrapper.
Check out this post as well: Send emails using PHPMailer
You can put those files anywhere you want, but the easiest way would be as a plugin, I guess, if need be, you can write a simple wrapper.
Check out this post as well: Send emails using PHPMailer