Managing a shared mailbox

Hi,

we are using Dynamics 365 and we do have a shared mailbox in Office 365. We are using the Outlook Add-In with Outlook 2016 and have added the shared mailboxes to all users that work on the shared mailbox. What are the best practices to jointly work on incoming e-mails in Outlook 2016? Currently we are facing the following issues:

1. The Outlook Add-In consumes much resources so that many users reject to use it, since that kills productivity in Outlook
2. Tracking the E-Mail is time consuming
3. Viewing the conversation history takes a long time to open is tedious to use
4. It's hard to tell who is working on which e-mail in Outlook (we using Outlook categories as workaround)
5. Dynamics mobile app is to slow and tedious to use. No  integration to mobile Outlook App

Do you know add-on that helps. Other CRM solutions that import the data from Dynamics 365?

Any help appreciated. 

John