I'm looking for a newsletter plugin recommendations. The plugin must be compatible with PHP 5.1.6 and WordPress 3.0 or newer and be easy to configure and use templates to be able to customize the newsletters. I've tried MailPress but it requires PHP 5.2. Most of the plugins I find in the repository use external services and I don't like to depend on them.
Can any one of you recommend me any plugin?
Thanks in advance