Create an allinit@domain.com.au Shared Mailbox on each Microsoft 365 tenant
1. Visit https://portal.office.com/ and login with admin credentials.
2. Navigate to Microsoft 365 Admin Centre.
3. Select Groups>Shared Mailbox.
4. Add a Shared Mailbox. Username is Allinit and User ID should be allinit@domain.com.au. Your shared mailbox is now created.
5. Now enable forwarding to that shared mailbox by clicking on it and clicking Email Forwarding.
6. Create the Forwarding to alit@allinit.com.au
Note: External Forwarding must be enabled on the tenant.