Link contact emails together

For example, when you have a repeat client (primary email), you may want to associate a second person with this client, so you don’t have to add the second person manually for each new project.

Another example: on a purchase order, you may want to add a second person’s email related to the same supplier — a main contact and a secondary contact. Right now, users have to search for the email and add it manually each time they send a PO.