There are many ways to communicate with colleagues over the Internet. We will use this space to explore several options. We are familiar with our local email. We can send personal messages or we can send messages to the whole school or the entire district depending what address we use to send our message.
Many sites invite people of similar interests to join a mailring sponsored by that site.
After joining, one will start receiving email addressed to the whole group of people. You might receive one digest every few days, or 3-4 in a day. The digests are especially handy for groups where you prefer to read more than respond. Many websites offer mailrings. For teachers some of the best options are found at teachers.net.