curl --request GET \
  --url https://api.example.com/api/Messages/Activities/Emails/{activityId}

{
  "activityID": 123,
  "userId": 123,
  "customerId": 123,
  "body": "<string>",
  "subject": "<string>",
  "attachments": 123,
  "messageDate": "2023-11-07T05:31:56Z",
  "createdDate": "2023-11-07T05:31:56Z",
  "to": "<string>",
  "cc": "<string>",
  "bcc": "<string>",
  "from": "<string>",
  "deleted": true,
  "isEncrypted": true
}