To add a new inbox to your company click the Add new inbox button on the Inbox tab, this will bring up the form to complete to add a new inbox. The mandatory fields are Inbox type, Display name, and Subscription, however, there are other options to select. 

Email notifications allow an email address to receive notifications for the inbox being created. 

Contact lookup allows you to connect the inbox to a Microsoft 365 account.

Assign users allows you to assign users to the inbox

Another feature that can be used when completing the inbox fields on the Admin Portal is to be able to save and add another inbox, making the process quicker to add multiple inboxes at once. 

Whilst adding a new inbox it is possible to add a new user and assign this user to the inbox. 

In the new inbox form, click the + button next to the Assign user field, this will allow you to go to a new user form to complete.