Content-Type: multipart/mixed; boundary="ab"

body

---- EXPECTED STRUCTURE ----{
  "headers_rfc": {},
  "html_body": [],
  "text_body": [],
  "attachments": [
    0
  ],
  "parts": [
    {
      "Text": {
        "headers_rfc": {
          "content_type": {
            "ContentType": {
              "c_type": "multipart",
              "c_subtype": "mixed",
              "attributes": {
                "boundary": "ab"
              }
            }
          }
        },
        "is_encoding_problem": false,
        "body": "body\n"
      }
    }
  ],
  "structure": {
    "Part": 0
  },
  "offset_header": 0,
  "offset_body": 46,
  "offset_end": 51
}