curl --request GET \
  --url https://app.herondata.io/api/end_users/{end_user_id_or_heron_id}/emails \
  --header 'x-api-key: <api-key>'

[
  {
    "cc_addresses": [
      "<string>"
    ],
    "created": "2023-11-07T05:31:56Z",
    "date_sent": "2023-11-07T05:31:56Z",
    "date_sent_string": "<string>",
    "from_address": "<string>",
    "from_address_domain": "<string>",
    "from_name": "<string>",
    "heron_id": "<string>",
    "html_body": "<string>",
    "html_or_text_body": "<string>",
    "is_reply": true,
    "reply_to": "<string>",
    "subject": "<string>",
    "subject_cleaned": "<string>",
    "text_body": "<string>",
    "to_addresses": [
      "<string>"
    ],
    "viewer_url": "<string>"
  }
]