post https://api.smtp2go.com/v3/allowed_senders/update
Replace the email addresses and domain names on your Allowed or Restricted Senders List using this endpoint. How the email addresses and domain names are used is defined in the current 'mode' value - further details of these modes are found in the SMPT2GO Guides. Note that a post to this endpoint will return a success, even if the setting is not in use.