A message with its attachments stripped: the header fields plus the bodies.
text_body is always plain text — a message that carries only HTML is rendered to text. html_body is only set when the message actually carries an HTML part.
text_body
html_body
@type t() :: %EmailParser.Email{ headers: %{required(String.t()) => String.t()}, html_body: String.t() | nil, text_body: String.t() | nil }