       iex> email = new |> from("tony@stark.com")
       %Swoosh.Email{from: {"", "tony@stark.com"}, [...]}
       iex> Memory.push(email)
-      %Swoosh.Email{from: {"", "tony@stark.com"}, headers: %{"Message-ID": "A1B2C3"}, [...]}
+      %Swoosh.Email{from: {"", "tony@stark.com"}, headers: %{"Message-ID": "a1b2c3"}, [...]}
       iex> Memory.get("A1B2C3")
-      %Swoosh.Email{from: {"", "tony@stark.com"}, headers: %{"Message-ID": "A1B2C3"}, [...]}
+      %Swoosh.Email{from: {"", "tony@stark.com"}, headers: %{"Message-ID": "a1b2c3"}, [...]}
   """
   def get(id) do
     GenServer.call(__MODULE__, {:get, id})

  end

  def handle_call({:get, id}, _from, state) do
    email = Enum.find(state, nil, fn %Swoosh.Email{headers: %{"Message-ID" => mid}} -> mid == id end)
    {:reply, email, state}
  end


      iex> email = new |> from("tony@stark.com")
      %Swoosh.Email{from: {"", "tony@stark.com"}, [...]}
      iex> Memory.push(email)
      %Swoosh.Email{from: {"", "tony@stark.com"}, headers: %{"Message-ID": "a1b2c3"}, [...]}
      iex> Memory.delete_all()
      :ok
      iex> Memory.list()
