curl --request GET \
  --url https://api.sentvia.ai/v1/messages/{id} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "thread_id": "<string>",
  "direction": "<string>",
  "from_addr": "<string>",
  "to_addrs": [
    "<string>"
  ],
  "subject": "<string>",
  "body_text": "<string>",
  "delivery_status": "<string>"
}