phplist

Phplist is a php and advanced newsletter manager in MySQL which allows you to efficiently administer a database with over 100,000 subscribers, all from their online interface.

It has the capability to feature various interesting features such as open an email and keep the recorded clicks in each. You can then count the statistics by message, subscriber, or URL

Phplist also supports sending and sending RSS based newsletters. Batch processing, message encryption, and some other throttling applications.

You can create your newsletter from Faplest's interface using FaxCista. Message format can be HTML or plain text. And, naturally, you can program when each is sent.

Finally, phplist includes several templates that you can personalize to include subscribe form on your own webpage.