I can email to leads/ contacts by creating segments for each.
This is crucial as we have substantial number of leads and contacts in the CRM. - if you create two customer journeys for leads/contacts then I am concerned that when a person is listed as a contact as well as a lead, that he will receive two emails.
I need to be able to create one dynamic segment that contains both leads and contacts (and also future ones that are added). Then I can create one journey that sends an email to this segment. This journey will also need to be able to automatically make sure that an email is only sent once to an email address (even if this email is associated with a lead AND a contact or if one lead/contact is in the segment multiple times)