MS Dynamics email integration

Hello all,

I have a potential scenario where one of our businesses has a MS Dynamics 365 instance in their own tenant.  They have a requirement to integrate with the group email system.

The group email system will reside in it's own tenant with Exchange Online.

I understand that connecting MSD365 email to Exchange Online is not supported "cross-tenant" but we're not in a position to migrate the Dynamics instance into the group tenant.  I imagine there are quite a few corps who might find themselves in this situation.

Does anyone have any advice as to how this might be achieved ?  We currently have POP/SMTP email via Gmail setup but this is not a favoured long term solution.

Many thanks

Andy