To view a specific inbox, click the inbox. This will open up a side panel which will display a snapshot of information for that inbox, to view the inbox in more detail this can be opened using the expand button. 

To edit a single inbox, click on the inbox to open the side panel and click Edit inbox. This can also be completed with a user expanded with the Edit inbox button. 

To edit multiple inboxes, tick the inboxes you would like to make changes to, this will display the option for Bulk action where the following changes can be made for multiple inboxes:

To delete an inbox, click on the inbox to open the side panel, select the ellipsis and click Delete inbox, this can also be completed with a inbox expanded using the Delete inbox button. 

To delete multiple inboxes, select the inboxes by ticking them and then click the Delete inboxes button.