Auth2 O365 Best Practices for outbound email account (Shared mailbox vs dedicated mailbox for Sugar)

Hi team, 

We have a customer who configured Azure etc as per the SugarCRM documentation to set up the main outbound email account to work with Auth2.

All steps were taken and they have a 'shared mailbox' hello@....account that they use with other applications.
This is not a licensed mail account.

The problem:

The mailbox needs to be 'Authorised' as part of the final step in the setup for the auth2 connection with o365.

This has been authorised by the account from the main Administrator for O365 at their company (John).

When emails are sent from Sugar, the sent emails are visible from John's personal sent folder.

Apparently, this is not an issue using a 'shared mailbox' with other applications - but it's a problem with Sugar.

Question

Do other O365 users create a dedicated mailbox for the outbound email account in Sugar? Or have you found a way of using a 'shared mailbox' authorized by another user and the sent messages going to that shared account?

Many thanks for reading and your input.

Cheers, JB