       %Swoosh.Email{from: {"", "tony.stark@example.com"}, headers: %{"Message-ID": "a1b2c3"}, [...]}
   """
   def push(email) do
-    GenServer.call(__MODULE__, {:push, email})
+    GenServer.call({:global, __MODULE__}, {:push, email})
   end
 
   @doc ~S"""

      [%Swoosh.Email{from: {"", "tony.stark@example.com"}, headers: %{"Message-ID": "a1b2c3"}, [...]}]
  """
  def all() do
    GenServer.call(__MODULE__, :all)
  end

  @doc ~S"""

      0
  """
  def pop() do
    GenServer.call({:global, __MODULE__}, :pop)
  end

  @doc ~S"""
