Wordpress Newsletter Mailing List Plugins - free

So, I'm in need of a simple newsletter mailing list manager. I've been using Subscribe2 and it's really good for sending updates for each post. Has a user manager with import and export. Overall it's really nice. It however is not really simple. I need really simple for my clients. So I'm looking at the following: Newletter http://wordpress.org/extend/plugins/newsletter/ Mailpress http://wordpress.org/extend/plugins/mailpress/ both seem really simple and FREE! If you like them, I really recommend donating or upgrading with newsletter. In the end, I ended up using Newsletter because I found it easiest to setup and start using. Plus, it imported my 15,000 users quite easily.