put https://api.actonsoftware.com/api/1/list//record
Update an existing record or insert a new contact record using the email address that you specify using the following logic:
If the email address exists in the list, only the first record matching that email address is updated with the data you provide.
If the email address is not already in the list, a new record is added.
Please take note that this means that any duplicate records are NOT updated.