Collaborative Inboxes in Google Workspace offer a way of sharing a mailbox with multiple users. A Google Group is created with a specific email address, and the people that need to access the shared mailbox are added as group members. 

Once a message is received in the collaborative inbox, group members can:

You will receive an email invitation to join a collaborative inbox. Open the message and click on Accept this invitation to join the group. 

Collaborative inboxes are created and managed using Google Groups, which can be viewed by clicking on the App Launcher button on any Google Workspace screen and choosing Groups

To see the collaborative inboxes that you have access to, click on My Groups on the left-hand side of the screen.

Click on the group you wish to access. 

Click on the Star button to the right of a group to add it to your Favourites list for easy access.