Google groups can be used like a mailing-list through its e-mail interface.
To subscribe to the Minix3 Google Group you send an e-mail to:
minix3+subscribe@googlegroups.com
You will receive an e-mail from Google and when you reply you are subscribed. From then on all the messages in the group will be send to your e-mail address.
To send a message to the group you send it to:
minix3@googlegroups.com
To respond to a message you just reply to the message within your mail program.
To unsubscribe you send an e-mail to:
minix3+unsubscribe@googlegroups.com