PrivateContent Mail Actions addon fills the last missing part of PrivateContent giving you a complete membership solution.
Link to download PrivateContent Mail Actions 1.63 WordPress Plugin Free is after the description.
Note: this is an add-on. You must have at least PrivateContent v6 to use it.
Enable just what you need, each module can be used singly, the only thing required is an e-mail. Plus, each mail is fully customizable by you using the handy WP editor!
Sometimes you need to contact users quickly and have no time to setup whole MailChimp system. Mail Actions has got a really fast system for this: just write mail title, text and choose which user categories (or single users) want to reach.