Group Email Services
eMailDodo - Group Email Service
eMailDodo makes it easy to email groups via — email and SMS text message as well as iPhone and Android apps.
Google Groups - Free Group Email Service
Discussions at Google Groups can be conducted entirely by email — or via the web. Of course, you can also create announcement-only lists to distribute messages — or collaborate on wiki-like pages with your group's members.
Yahoo! Groups - Free Group Email Service
Yahoo! Groups lets you manage even large groups with ease. Each member can pick their most desired delivery method (individual messages, digests, or maybe reading via the web or an RSS news feed), and you can even send preset messages on a schedule.