New to Elixir would like some feedback

I’m new to elixir and would really like some feedback on my code. MY background has been node -> laravel -> ruby / rails -> go -> elixir. I’m building an SMTP client and would like to make sure I’m using common patterns before I continue.

Any feedback would be appreciated.

defmodule Client do
  @moduledoc """
  Documentation for `Smtpclient`.
  """

  use Agent

  def start_link(_opts) do
    Agent.start_link(fn -> %{} end, name: __MODULE__)
  end


  def connect(pid, tld) do
      set_value(pid, "tld", tld)
      {:ok, records} = DNS.resolve(tld, :mx)
      Enum.sort_by(records, fn(r) -> elem(r, 0) end)
      sock = do_connect(records, 0)
      set_socket(pid, sock)
      set_value(pid, "hostname", tld)
      {:ok, sock}
  end

  @spec helo(any) :: any
  def helo(pid) do
      already_helloed = get_value(pid, "already_helloed")
      if already_helloed do # if already helloed return early
        {:error, "already helloed"}
      end
      sock = get_socket(pid)
      tld = get_value(pid, "tld")
      sock |> Socket.Stream.send!("HELO #{tld}")
      set_value(pid, "already_helloed", true)
      sock |> Socket.Stream.recv!
  end

  def noop(pid) do
    try do
      sock = get_socket(pid)
      sock |> Socket.Stream.send!("NOOP")
      sock |> Socket.Stream.recv!
    rescue
      Socker.Error -> {:error, :no_connection}
    end
  end

  def quit(sock) do
      try do
        sock |> Socket.Stream.send!("QUIT")
        sock |> Socket.Stream.recv!
        sock |> Socket.close!()
      rescue
        Socket.Error -> {:error, "something is wrong"}
      end
  end

  def rctp_to(pid, email) do
    try do
      sock = get_socket(pid)
      sock |> Socket.Stream.send!("RCPT_TO #{email}")
      sock |> Socket.Stream.recv!
    rescue
      Socker.Error -> {:error, "something is wrong"}
    end
  end

  defp set_socket(pid, sock) do
    Agent.update(pid, &Map.put(&1, "socket", sock))
  end

  defp get_socket(pid) do
    Agent.get(pid, &Map.get(&1, "socket"))
  end

  defp set_value(pid, key, value) do
    Agent.update(pid, &Map.put(&1, key, value))
  end

  defp get_value(pid, key) do
    Agent.get(pid, &Map.get(&1, key))
  end

  defp do_connect(hostnames, i) do
    try do
      host = elem(Enum.at(hostnames, i), 1)
      Socket.TCP.connect!(to_string(host), 25, packet: :line)
    rescue
        Socket.Error ->
          if Enum.at(hostnames, i) == nil do
            {:error, "all mx servers down"}
          end
          do_connect(hostnames, i + 1)
    end
  end
end