Email validation according to RFC 5322 with Elixir and gen_smtp

email_validation.ex

import Ecto.Changeset

@spec validate_email(Ecto.Changeset.t(), atom) :: Ecto.Changeset.t()
def validate_email(changeset, field) when is_atom(field) do
  changeset
  |> validate_length(field, max: 160)
  |> validate_change(field, &validate_email_rfc5322/2)
end

defp validate_email_rfc5322(field, email) do
  charlist = String.to_charlist(email)

  with {:ok, tokens, _} <- :smtp_rfc5322_scan.string(charlist),
       {:ok, _} <- :smtp_rfc5322_parse.parse(tokens) do
    []
  else
    _ -> [{field, {"is invalid", validation: :format}}]
  end
rescue
  _ -> [{field, {"is invalid", validation: :format}}]
end