Gaggle Mail - Gaggle Mail is a simple and easy to use email list manager.
Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.
Tempinbox - Tempinbox is a free temporary email service to receive disposable mail. It can also be used as temp mail or 10 minute email, or use it for trash mail.
Bigtent - BigTent is a web-based organization and communication portal for groups.
TempMailGen - The best temp mail generator. Get unlimited temporary email inboxes for lifetime access.
Nabble - Nabble is a forum software that are embeddable and fully customizable with scripting language.