post
https://api.postgrid.com/print-mail/v1/contacts
Creates a new contact. Will also verify the address if created with the live API key. To successfully create a contact, either a firstName, companyName, or both is required. You can supply both, but you cannot supply neither.
Note that if you create a contact that has identical information to another contact, this will simply update the description of the existing contact and return it. This avoids creating duplicate contacts.