In previous version of Odoo, mail channels had a feature "Send messages by email". Apparently this feature was removed in Odoo 16 and the documentation is outdated:

https://www.odoo.com/documentation/16.0/applications/productivity/discuss/overview/team_communication.html#use-a-channel-as-a-mailing-list

How can we achieve a similar functionality in Odoo 16? 

The issue is, if I add a contact without a login as channel member, it does not receive emails. (Only, when directly mentioned with "@") . How can I make these channel members without a login to receive emails for all messages?