diff --git a/config/config.exs b/config/config.exs
index 408948a..ed1c192 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -1,3 +1,7 @@
 import Config
 
+if Mix.env() == :test do
+  config :logger, level: :info
+end
+
 # import_config "#{Mix.env}.exs"
diff --git a/lib/bamboo/adapters/render/raw.ex b/lib/bamboo/adapters/render/raw.ex
index 1f3d840..b72c9ac 100644
--- a/lib/bamboo/adapters/render/raw.ex
+++ b/lib/bamboo/adapters/render/raw.ex
@@ -3,83 +3,195 @@ defmodule BambooSes.Render.Raw do
   Functions for rendering email messages into strings.
   """
 
+  # TODO render according to logic table: text, html, has_attachments, has_content_id_attachments
   @doc """
   Returns a tuple with all data needed for the underlying adapter to send.
   """
   def render(email, extra_headers \\ []) do
-    email
-    # Returns a list of tuples
-    |> compile_parts()
-    # Nests the tuples and attaches necessary metadata
-    |> nest_parts(email, extra_headers)
+    has_text = String.length(email.text_body) > 0
+    has_html = String.length(email.html_body) > 0
+    has_attachments = length(filter_regular_attachments(email)) > 0
+    has_inline_attachments = length(filter_inline_attachments(email)) > 0
+
+    headers = headers_for(email) ++ extra_headers
+
+    build_parts(
+      has_text,
+      has_html,
+      has_attachments,
+      has_inline_attachments,
+      email,
+      headers
+    )
+    # |> IO.inspect()
     |> :mimemail.encode()
+
+    # has_attachments = 
+    # email
+    # # Returns a list of tuples
+    # |> compile_parts()
+    # # Nests the tuples and attaches necessary metadata
+    # |> nest_parts(email, extra_headers)
+    # |> :mimemail.encode()
+  end
+
+  defp build_parts(false, false, _, _, email, headers) do
+    {
+      "multipart",
+      "mixed",
+      headers,
+      %{},
+      prepare_attachments(email.attachments)
+    }
   end
 
-  defp nest_parts(parts, email, extra_headers) do
-    {top_mime_type, top_mime_sub_type, _, _, top_content_part} = nested_content_part_tuples(parts)
+  defp build_parts(false, true, false, false, email, headers) do
+    {
+      "text",
+      "html",
+      headers,
+      parameters_for(nil),
+      email.html_body
+    }
+  end
 
+  defp build_parts(false, true, false, true, email, headers) do
     {
-      top_mime_type,
-      top_mime_sub_type,
-      headers_for(email) ++ extra_headers,
+      "multipart",
+      "related",
+      headers,
       %{},
-      top_content_part
+      [
+        # generates html
+        build_parts(false, true, false, false, email, [])
+      ] ++ prepare_attachments(filter_inline_attachments(email))
     }
   end
 
-  defp nested_content_part_tuples(parts) do
-    plain_part_tuple = body_part_tuple(parts, :plain)
-    html_part_tuple = body_part_tuple(parts, :html)
-    # attachment_part_tuples(parts)
-    inline_attachment_part_tuples = []
-    attached_attachment_part_tuples = attachment_part_tuples(parts)
-
-    related_or_html_part_tuple =
-      if Enum.empty?(inline_attachment_part_tuples) do
-        html_part_tuple
-      else
-        if is_nil(html_part_tuple),
-          do: nil,
-          else:
-            {"multipart", "related", [], %{}, [html_part_tuple | inline_attachment_part_tuples]}
-      end
-
-    alternative_or_plain_tuple =
-      if is_nil(related_or_html_part_tuple) do
-        plain_part_tuple
-      else
-        {"multipart", "alternative", [], %{}, [plain_part_tuple, related_or_html_part_tuple]}
-      end
-
-    mixed_or_alternative_tuple =
-      if Enum.empty?(attached_attachment_part_tuples) do
-        alternative_or_plain_tuple
-      else
-        if is_nil(alternative_or_plain_tuple),
-          do: nil,
-          else:
-            {"multipart", "mixed", [], %{},
-             [alternative_or_plain_tuple | attached_attachment_part_tuples]}
-      end
-
-    mixed_or_alternative_tuple
-  end
-
-  @spec body_part_tuple([tuple()], atom()) :: nil | tuple()
-  defp body_part_tuple(parts, type) do
-    part = Enum.find(parts, &(elem(&1, 0) == type))
-
-    if is_nil(part) do
-      nil
-    else
-      {
-        mime_type_for(part),
-        mime_subtype_for(part),
-        headers_for(part),
-        parameters_for(part),
-        elem(part, 1)
-      }
-    end
+  defp build_parts(false, true, true, false, email, headers) do
+    {
+      "multipart",
+      "mixed",
+      headers,
+      %{},
+      [
+        # generates html
+        build_parts(false, true, false, false, email, [])
+      ] ++ prepare_attachments(email.attachments)
+    }
+  end
+
+  defp build_parts(false, true, true, true, email, headers) do
+    {
+      "multipart",
+      "mixed",
+      headers,
+      %{},
+      [
+        # generates html
+        build_parts(false, true, false, true, email, [])
+      ] ++ prepare_attachments(filter_regular_attachments(email))
+    }
+  end
+
+  defp build_parts(true, false, false, false, email, headers) do
+    {
+      "text",
+      "plain",
+      headers,
+      parameters_for(nil),
+      email.text_body
+    }
+  end
+
+  defp build_parts(true, false, _, _, email, headers) do
+    {
+      "multipart",
+      "mixed",
+      headers,
+      %{},
+      [
+        # generates text
+        build_parts(true, false, false, false, email, [])
+      ] ++ prepare_attachments(email.attachments)
+    }
+  end
+
+  defp build_parts(true, true, false, false, email, headers) do
+    {
+      "multipart",
+      "alternative",
+      headers,
+      %{},
+      [
+        # generates text
+        build_parts(true, false, false, false, email, []),
+        # generates html
+        build_parts(false, true, false, false, email, [])
+      ]
+    }
+  end
+
+  defp build_parts(true, true, false, true, email, headers) do
+    {
+      "multipart",
+      "related",
+      headers,
+      %{},
+      [
+        # generates alternative
+        build_parts(true, true, false, false, email, [])
+      ] ++ prepare_attachments(filter_inline_attachments(email))
+    }
+  end
+
+  defp build_parts(true, true, true, false, email, headers) do
+    {
+      "multipart",
+      "mixed",
+      headers,
+      %{},
+      [
+        # generates alternative
+        build_parts(true, true, false, false, email, [])
+      ] ++ prepare_attachments(email.attachments)
+    }
+  end
+
+  defp build_parts(true, true, true, true, email, headers) do
+    {
+      "multipart",
+      "mixed",
+      headers,
+      %{},
+      [
+        # generates related with alternative
+        build_parts(true, true, false, true, email, [])
+      ] ++ prepare_attachments(filter_regular_attachments(email))
+    }
+  end
+
+  defp prepare_attachments(attachments) do
+    attachments
+    |> Enum.map(fn attachment -> {:attachment, attachment.data, attachment} end)
+    |> attachment_part_tuples()
+  end
+
+  def filter_inline_attachments(email) do
+    Enum.filter(email.attachments, fn
+      attachment ->
+        !is_nil(attachment) &&
+          !is_nil(attachment.content_id) &&
+          String.length(attachment.content_id) > 0
+    end)
+  end
+
+  def filter_regular_attachments(email) do
+    Enum.filter(email.attachments, fn
+      attachment ->
+        !is_nil(attachment) &&
+          (is_nil(attachment.content_id) || String.length(attachment.content_id) == 0)
+    end)
   end
 
   @spec attachment_part_tuples([tuple()]) :: list(tuple())
@@ -171,21 +283,4 @@ defmodule BambooSes.Render.Raw do
   end
 
   defp mailbox({name, address}), do: "#{name} <#{address}>"
-
-  defp compile_parts(email) do
-    [
-      {:plain, email.text_body},
-      {:html, email.html_body},
-      Enum.map(email.attachments, fn attachment ->
-        {:attachment, attachment.data, attachment}
-      end)
-    ]
-    |> List.flatten()
-    |> Enum.filter(&not_empty_tuple_value(&1))
-  end
-
-  defp not_empty_tuple_value(tuple) when is_tuple(tuple) do
-    value = elem(tuple, 1)
-    value != nil && value != [] && value != ""
-  end
 end
diff --git a/test/lib/bamboo/adapters/content_raw_parts_text.exs b/test/lib/bamboo/adapters/content_raw_parts_text.exs
new file mode 100644
index 0000000..a440ef4
--- /dev/null
+++ b/test/lib/bamboo/adapters/content_raw_parts_text.exs
@@ -0,0 +1,354 @@
+defmodule BambooSes.ContentRawPartsTest do
+  use ExUnit.Case
+  alias BambooSes.Message.Content
+  alias BambooSes.{EmailParser, TestHelpers}
+  alias Bamboo.Email
+
+  @moduledoc """
+
+  TEXT | HTML | ATTACHMENTS | INLINE ATTACHMENTS | RESULT
+  f    | f    | f           | f                  | NOT VALID
+  f    | f    | f           | t                  | mixed(attachments[])
+  f    | f    | t           | f                  | mixed(attachments[])
+  f    | f    | t           | t                  | mixed(attachments[])
+  f    | t    | f           | f                  | text/html
+  f    | t    | f           | t                  | related(html,inline_attachments[])
+  f    | t    | t           | f                  | mixed(html,attachments[])
+  f    | t    | t           | t                  | mixed(related(html,inline_attachments[]),attachments[])
+  t    | f    | f           | f                  | text/plain
+  t    | f    | f           | t                  | mixed(text,attachments[])
+  t    | f    | t           | f                  | mixed(text,attachments[])
+  t    | f    | t           | t                  | mixed(text,attachments[])
+  t    | t    | f           | f                  | alternative(text,html)
+  t    | t    | f           | t                  | related(alternative(text,html),inline_attachments[])
+  t    | t    | t           | f                  | mixed(alternative(text,html),attachments[])
+  t    | t    | t           | t                  | mixed(related(alternative(text,html),inline_attachments[]),attachments[])
+
+  """
+
+  @doc "f f f t"
+  test "generates multipart/mixed when only inline attachments are provided; no text, no html" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("")
+      |> Email.html_body("")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/pole.png"),
+        content_id: "img-1"
+      )
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [png]} = EmailParser.parse(raw_data)
+    assert {"image", "png", _, _, _} = png
+  end
+
+  @doc "f f t f"
+  test "generates multipart/mixed when only regular attachments are provided; no text, no html" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("")
+      |> Email.html_body("")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/invoice.pdf"))
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [pdf]} = EmailParser.parse(raw_data)
+    assert {"application", "pdf", _, _, _} = pdf
+  end
+
+  @doc "f f t t"
+  test "generates multipart/mixed when inline and regular attachments are provided; no text, no html" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("")
+      |> Email.html_body("")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/pole.png"),
+        content_id: "img-1"
+      )
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/invoice.pdf"))
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [pdf, png]} = EmailParser.parse(raw_data)
+    assert {"application", "pdf", _, _, _} = pdf
+    assert {"image", "png", _, _, _} = png
+  end
+
+  @doc "f t f f"
+  test "generates text/html when only html is provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("")
+      |> Email.html_body("<b>Email body</b>")
+      |> Email.put_header("X-Custom-Header", "custom-value")
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"text", "html", _, _, "<b>Email body</b>"} = EmailParser.parse(raw_data)
+  end
+
+  @doc "f t f t"
+  test "generates multipart/related when html and attachments with content_id are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("")
+      |> Email.html_body("<b>Email body</b><img src=\"cid:img-1\" />")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/pole.png"),
+        content_id: "img-1"
+      )
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "related", _, _, [html, png]} = EmailParser.parse(raw_data)
+    assert {"text", "html", _, _, "<b>Email body</b><img src=\"cid:img-1\" />"} = html
+    assert {"image", "png", _, _, _} = png
+  end
+
+  @doc "f t t f"
+  test "generates multipart/mixed when html and attachments are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("")
+      |> Email.html_body("<b>Email body</b>")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/invoice.pdf"))
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [html, pdf]} = EmailParser.parse(raw_data)
+    assert {"text", "html", _, _, "<b>Email body</b>"} = html
+    assert {"application", "pdf", _, _, _} = pdf
+  end
+
+  @doc "f t t t"
+  test "generates multipart/mixed with multipart/related" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("")
+      |> Email.html_body("<b>Email body</b><img src=\"cid:img-1\" />")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/pole.png"),
+        content_id: "img-1"
+      )
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/invoice.pdf"))
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [related, pdf]} = EmailParser.parse(raw_data)
+    assert {"multipart", "related", _, _, [html, png]} = related
+    assert {"application", "pdf", _, _, _} = pdf
+    assert {"text", "html", _, _, "<b>Email body</b><img src=\"cid:img-1\" />"} = html
+    assert {"image", "png", _, _, _} = png
+  end
+
+  @doc "t f f f"
+  test "generates text/plain when only text is provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("Email text body")
+      |> Email.html_body("")
+      |> Email.put_header("X-Custom-Header", "custom-value")
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"text", "plain", _, _, "Email text body"} = EmailParser.parse(raw_data)
+  end
+
+  @doc "t f f t"
+  test "generates multipart/mixed when text and inline attathments are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("Email text body")
+      |> Email.html_body("")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/pole.png"),
+        content_id: "img-1"
+      )
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [text, png]} = EmailParser.parse(raw_data)
+    assert {"text", "plain", _, _, "Email text body"} = text
+    assert {"image", "png", _, _, _} = png
+  end
+
+  @doc "t f t f"
+  test "generates multipart/mixed when text and attachments are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("Email text body")
+      |> Email.html_body("")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/invoice.pdf"))
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [text, pdf]} = EmailParser.parse(raw_data)
+    assert {"text", "plain", _, _, "Email text body"} = text
+    assert {"application", "pdf", _, _, _} = pdf
+  end
+
+  @doc "t f t t"
+  test "generates multipart/mixed when text and both inline and regular attachments are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("Email text body")
+      |> Email.html_body("")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/pole.png"),
+        content_id: "img-1"
+      )
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/invoice.pdf"))
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [text, pdf, png]} = EmailParser.parse(raw_data)
+    assert {"text", "plain", _, _, "Email text body"} = text
+    assert {"image", "png", _, _, _} = png
+    assert {"application", "pdf", _, _, _} = pdf
+  end
+
+  @doc "t t f f"
+  test "generates multipart/alternative when text and html are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("Email text body")
+      |> Email.html_body("<b>Email html body</b>")
+      |> Email.put_header("X-Custom-Header", "custom-value")
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "alternative", _, _, [text, html]} = EmailParser.parse(raw_data)
+    assert {"text", "plain", _, _, "Email text body"} = text
+    assert {"text", "html", _, _, "<b>Email html body</b>"} = html
+  end
+
+  @doc "t t f t"
+  test "generates multipart/related when text, html and inline attachments are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("Email text body")
+      |> Email.html_body("<b>Email html body</b>")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/pole.png"),
+        content_id: "img-1"
+      )
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "related", _, _, [alternative, png]} = EmailParser.parse(raw_data)
+    assert {"multipart", "alternative", _, _, [text, html]} = alternative
+    assert {"image", "png", _, _, _} = png
+    assert {"text", "plain", _, _, "Email text body"} = text
+    assert {"text", "html", _, _, "<b>Email html body</b>"} = html
+  end
+
+  @doc "t t t f"
+  test "generates multipart/mixed when text, html and regular attachements are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("Email text body")
+      |> Email.html_body("<b>Email html body</b>")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/invoice.pdf"))
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [alternative, pdf]} = EmailParser.parse(raw_data)
+    assert {"multipart", "alternative", _, _, [text, html]} = alternative
+    assert {"text", "plain", _, _, "Email text body"} = text
+    assert {"text", "plain", _, _, "Email text body"} = text
+    assert {"text", "html", _, _, "<b>Email html body</b>"} = html
+    assert {"application", "pdf", _, _, _} = pdf
+  end
+
+  @doc "t t t t"
+  test "generates multipart/mixed when text, html and both inline and regular attachements are provided" do
+    content =
+      TestHelpers.new_email()
+      |> Email.text_body("Email text body")
+      |> Email.html_body("<b>Email html body</b>")
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/pole.png"),
+        content_id: "img-1"
+      )
+      |> Email.put_attachment(Path.join(__DIR__, "../../../support/invoice.pdf"))
+      |> Content.build_from_bamboo_email()
+
+    %Content{
+      Raw: %{
+        Data: raw_data
+      }
+    } = content
+
+    assert {"multipart", "mixed", _, _, [related, pdf]} = EmailParser.parse(raw_data)
+    assert {"multipart", "related", _, _, [alternative, png]} = related
+    assert {"multipart", "alternative", _, _, [text, html]} = alternative
+    assert {"image", "png", _, _, _} = png
+    assert {"text", "plain", _, _, "Email text body"} = text
+    assert {"application", "pdf", _, _, _} = pdf
+    assert {"text", "html", _, _, "<b>Email html body</b>"} = html
+  end
+end
diff --git a/test/support/pole.png b/test/support/pole.png
new file mode 100644
index 0000000..3fda0cc
Binary files /dev/null and b/test/support/pole.png differ