For every contact in Dynamics 365, the 'Email' flag has to set to 'Allow' in the Contact Preferences section, for the system to send out e-mails. In a few use cases, we are making use of journeys to send out communication for purposes other than marketing i.e., information about appointments, etc. This doesn't required consent for marketing communication.

But not all contacts can't be set to allow e-mail. If there is a feature to override contact preference for a certain journey meant for non-marketing purposes, it would be really great.