SchoolCircle is a free service that is designed to help elementary school teachers organize communication to the parents of their students. SchoolCircle offers many of the features of Google+ Communities without the need for parents to join Google+.
Through SchoolCircle you can create an online community for parents of students in your classroom. You can use SchoolCircle to send messages, organize tasks for parent-volunteers, and post updates about things happening in your classroom and in your school. Parents don't have to sign into SchoolCircle everyday because you can choose to send a daily digest of updates to their email addresses.
Applications for Education
If you're looking for a way to streamline your communication to parents, SchoolCircle might be what you need. It provides a solution that is a little more robust than email contact lists while not being so complex that it will take you or your students' parents a long time to learn how to use. My one wish for SchoolCircle is that they develop an option for sending text messages to parents.