Integrate MailPoet's (formerly WYSIJA) email list management plugin into IssueM's Leaky Paywall WordPress plugin. More info at http://LeakyP
This plugin allows you to choose which MailPoet list you would like to add a new subscriber to when someone pays and subscribes using IssueM's Leaky Paywall plugin. You can also choose which MailPoet list an expired subscriber demotes to, preserving their email address for future use.
More info at http://LeakyPW.com
You can follow this plugins development on GitHub