Subscription Plugin

Excuse me if I am posting this in the wrong section but I would like to know if anyone out there knows of a plugin I could use for wordpress site. I currently mail out newsletters to my clients for an annual fee. I would like to move this online to my website and need a plugin that would allow people to subscribe annually, which would give them access to a specif page or pages that would contain links to the newsletters. i already have a 2 checkout account and google checkout as well. i also might need this plug in to give free 3 day trials if possible..any help would be greatly appreciated. Thank You