Mass Mailing in php

While looking for a decent mass mailing solution for one of my projects , i found two solutions that might work for me , they are

1 ) Pommo - A php based mass mailing package

2 ) Swiftmailer - A php based library for mailings.

While the former is a ready made solution , it has a limitation , the API is not yet documented , which means in order to use it i my project , i will have to give it some time dissecting the code , and unfortunately , the deadline is close , so i took a swing at my other option

Swiftmailer is a robust library , it has a lot of features , while this one is also not properly documented ,it has SOME documentation , and its relatively easy to use and integrate in my code.

So , if you want a readymade mailer with a good interface ad features like groups etc, go for Pommo, if you want to integrate a mailer in your project , go for Swiftmailer.