How do you send mass emails using mysql details based on certain criteria?

I need to email my websites members easily based on certain criteria in the mysql database.

For example:

email all females that are over 25 yea开发者_StackOverflowrs old (assuming these variables are stored in the database)

I have installed and looked at phplist which seems great but I can't work out how to automatically add members to it when they sign up to my site and how to email based on criteria.

If theres a better way of doing it other than using something like phplist please let me know. I would like to be able to do this reasonably easily when sending out weekly emails.

Thanks

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I would suggest taking a look at PEAR and the mailing options it provides.