LSMailer is a modern and efficient library to send emails using SMTP driver. It can be use in simple projects, where there is a need for a simple way to send emails (as in contact forms, polls, etc).
It’s very easy to use, just one file to include and a SMTP account set up. Check the documentation to see how easy is to pass the configuration data to the class.
It has very intuitive methods, as to(), cc(), bcc(), send(). More than that, these methods are chainable, so you can always play in an elegant way with the parameters.
Also, for your convenience, there are 2 ways to deliver those parameters, either as a string, or as an array (if your project is producing such data).
It works with simple, TLS or SSL SMTP accounts. Debugging option also available (just use debug flag).
Check the concise documentation or for a quick start, the example php file supplied in the archive (mailer.php).
It requires at least PHP 5.3