Shared Email Issue

Hello John,

If i understand your request correctly, you need to have a sort of common account which can be either setup as standalone for which a license is needed, but in general practice if the mailbox will be added as an additional mailbox on to the primary email box, then you can consider using it as a shared mailbox which is free to use.

To grant permissions of mailboxes, you can do so with the GUI mode or powershell mode and the GUI is fairly simple and straight forward once you are at the Exchange Console.

A lot of information on how to configure the Shared Mailboxes for daily usage is described here

https://support.office.com/en-us/article/create-a-shared-mailbox-871a246d-3acd-4bba-948e-5de8be0544c9 

A more technically detailed (Exchange 2016, more or less on Office 365 powershell) article for permissions is listed here : https://technet.microsoft.com/en-us/library/jj919240(v=exchg.160).aspx 

Hope the above helps you.