Send new emails

mutation sendNewEmail($input: SendNewEmailInput!) {
  sendNewEmail(input: $input) {
    email {
      id
    }
    error {
      message
      type
      code
    }
  }
}

{
  "input": {
    "customerId": "c_01GTC6ZHCMAGR06FMPN9VY5J95",
    "threadId": "th_01HD44FHMCDSSWE38N14FSYV6K",
    "subject": "Your account has a problem",
    "textContent": "The plain text version of your email goes here.",
    "markdownContent": "The markdown **version** of your _email_ goes here."
  }
}