In this chapter, you will learn how to add extra functionality to your phpList installation by "hacking" the source code. Unlike the advanced features previously covered, none of the hacks covered in this chapter are officially supported by phpList and may not work in future versions. Instead of teaching you how to implement specific features, this chapter is aimed more at teaching the basic methods behind adding functionality to phpList by either making direct code changes or implementing pre-packaged, community-developed hacks.
We will cover the following hacks:
Substituting user attributes in the message subject line
Sending system messages formatted as HTML instead of plain text
Creating a messages archive page
Sending messages through your e-mail client