You can set up an email list using Google Groups, for instance. As an example for such a list, see https://news.ycombinator.com/item?id=44767555.

People need to subscribe to the mailing list, either by sending a subscribe email to the appropriate email address, or via a web interface that is specific to the mailing list server. Once subscribed, you simply send emails to the list’s email address, and receive emails from that address. It’s useful to set up a filter in your email account or email client so that all messages from a given mailing list are automatically sorted into a separate email folder.