PHPlist is an open source software for managing mailing lists. It is designed for newsletters, news, advertising to list of subscribers management. It is developed in PHP and have MySQL database to store the information.Public interface is available in 35 languages. The documentation detailing the functions and features of the software is available in English and is partially translated into Spanish, French, and Dutch.
PHPlist can manage a list of subscribers and send e-mail messages to large numbers of subscribers. The subscription management, registration, personal data changes, and unsubscribe requests, are automated. Subscriptions to one or more lists are made through a subscription page that can be integrated into a website.The information requested during registration, for example, country, language, date of birth, favorite food, etc is determined by the list administrators and can be modified at any time.
This information can then be used for targeted messaging, you can send Newsletter to subscribers who meet certain criteria, such as country or city of residence.
The software is distributed free under GPL license.
Source: http://www.phplist.com/details