In some cases, you may wish to invite people from outside the organization to join or send messages to a private group. You can set permissions to Group owners can allow members from outside this domain, which will allow clients and other people from outside the organization to be invited to join certain discussions. You can also set a permission to Group owners can allow incoming email from outside this domain, which allows clients to use the group's email address to send messages. This is great for customer support:
It's recommended to create a group called Support that can only be seen by managers and owners, and set your support team as managers of this group. This allows people to send messages to [email protected] and only the support team will be able to see them.