I have the emails of about 10 people who would like to stay in contact to discuss a topic. It occurred to me: why not make it a list? But despite googling it for a bit, I still have no idea how to do this in the most legit way, especially for the rest of the group.
I think you are looking for something like mailman. It is a ‘many to many’ list server.
phpList is a ‘one to many’ server, where you can automatically send one message to many subscribers, but they cannot respond to the message in a way that reaches all of the other subscribers.