integration between PHP.MySQL, and mailing list

I have an issue that was mentioned by someone else a little earlier: Each day (and once a week), I want to be able to send out an email customized for an individual, based on a MySQL database. For example, I currently have it set up so that a cron job loads a php page using lynx. This page checks for people who need to be notified of a particular change in the website, and composes (and then sends) an email with their individual name and the changes they decided they wanted to be notified about. I can do without the individual names (although that's nice to have), but I need to take this concept to the next level. The site is currently in testing, so sending out up to 5 emails at a time is easy using the current system. However, I expect to send, at one time, hundreds or thousands of emails of this nature in the future, and it's ridiculous to even try to use mail() in PHP for that due to the system load. The email is not generic SPAM - the user customizes their account to select the notifications they want, and each notification (6 different ones) have to be generated based on currently available information from a database. One of them actually needs to be generated for each user. Again, this is easily done with just PHP, but the system load would quickly bring the server to a halt. (I _believe_ - if I'm wrong, and just using PHP would be fine, please let me know.) A mailing list system like Mailman seems pretty powerful, but I'm not sure how to integrate it with my needs. I believe that someone here must have implemented something similar to this, or explored the options. This is a new area of knowledge for me, and I'm not even sure where to start. Do any of you have any tips or URLs for me to look at? Thanks, Andrew Elliston ------------------------------------------------ Drew's Pad <http://www.elliston.net/drew/> ------------------------------------------------