diff --git a/lib/mail.ex b/lib/mail.ex
index 728029a..8533922 100644
--- a/lib/mail.ex
+++ b/lib/mail.ex
@@ -95,9 +95,6 @@ defmodule Mail do
     end)
   end
 
-  def get_text(%Mail.Message{headers: %{"content-type" => "text/plain" <> _}} = message),
-    do: message
-
   def get_text(%Mail.Message{headers: %{"content-type" => ["text/plain" | _]}} = message),
     do: message
 
@@ -261,8 +258,10 @@ defmodule Mail do
   @doc """
   Add a new `subject` header
 
-      Mail.put_subject(%Mail.Message{}, "Welcome to DockYard!")
-      %Mail.Message{headers: %{subject: "Welcome to DockYard!"}}
+  ## Examples
+
+      iex> Mail.put_subject(%Mail.Message{}, "Welcome to DockYard!")
+      %Mail.Message{headers: %{"subject" => "Welcome to DockYard!"}}
   """
   def put_subject(message, subject),
     do: Mail.Message.put_header(message, "subject", subject)
@@ -279,15 +278,17 @@ defmodule Mail do
   Recipients can be added as a single string or a list of strings.
   The list of recipients will be concated to the previous value.
 
-      Mail.put_to(%Mail.Message{}, "one@example.com")
-      %Mail.Message{headers: %{to: ["one@example.com"]}}
+  ## Examples
+
+      iex> Mail.put_to(%Mail.Message{}, "one@example.com")
+      %Mail.Message{headers: %{"to" => ["one@example.com"]}}
 
-      Mail.put_to(%Mail.Message{}, ["one@example.com", "two@example.com"])
-      %Mail.Message{headers: %{to: ["one@example.com", "two@example.com"]}}
+      iex> Mail.put_to(%Mail.Message{}, ["one@example.com", "two@example.com"])
+      %Mail.Message{headers: %{"to" => ["one@example.com", "two@example.com"]}}
 
-      Mail.put_to(%Mail.Message{}, "one@example.com")
-      |> Mail.put_to(["two@example.com", "three@example.com"])
-      %Mail.Message{headers: %{to: ["one@example.com", "two@example.com", "three@example.com"]}}
+      iex> Mail.put_to(%Mail.Message{}, "one@example.com")
+      iex> |> Mail.put_to(["two@example.com", "three@example.com"])
+      %Mail.Message{headers: %{"to" => ["one@example.com", "two@example.com", "three@example.com"]}}
 
   The value of a recipient must conform to either a string value or a tuple with two elements,
   otherwise an `ArgumentError` is raised.
@@ -319,15 +320,17 @@ defmodule Mail do
   Recipients can be added as a single string or a list of strings.
   The list of recipients will be concated to the previous value.
 
-      Mail.put_cc(%Mail.Message{}, "one@example.com")
-      %Mail.Message{headers: %{cc: ["one@example.com"]}}
+  ## Examples
 
-      Mail.put_cc(%Mail.Message{}, ["one@example.com", "two@example.com"])
-      %Mail.Message{headers: %{cc: ["one@example.com", "two@example.com"]}}
+      iex> Mail.put_cc(%Mail.Message{}, "one@example.com")
+      %Mail.Message{headers: %{"cc" => ["one@example.com"]}}
 
-      Mail.put_cc(%Mail.Message{}, "one@example.com")
-      |> Mail.put_cc(["two@example.com", "three@example.com"])
-      %Mail.Message{headers: %{cc: ["one@example.com", "two@example.com", "three@example.com"]}}
+      iex> Mail.put_cc(%Mail.Message{}, ["one@example.com", "two@example.com"])
+      %Mail.Message{headers: %{"cc" => ["one@example.com", "two@example.com"]}}
+
+      iex> Mail.put_cc(%Mail.Message{}, "one@example.com")
+      iex> |> Mail.put_cc(["two@example.com", "three@example.com"])
+      %Mail.Message{headers: %{"cc" => ["one@example.com", "two@example.com", "three@example.com"]}}
 
   The value of a recipient must conform to either a string value or a tuple with two elements,
   otherwise an `ArgumentError` is raised.
@@ -359,15 +362,17 @@ defmodule Mail do
   Recipients can be added as a single string or a list of strings.
   The list of recipients will be concated to the previous value.
 
-      Mail.put_bcc(%Mail.Message{}, "one@example.com")
-      %Mail.Message{headers: %{bcc: ["one@example.com"]}}
+  ## Examples
+
+      iex> Mail.put_bcc(%Mail.Message{}, "one@example.com")
+      %Mail.Message{headers: %{"bcc" => ["one@example.com"]}}
 
-      Mail.put_bcc(%Mail.Message{}, ["one@example.com", "two@example.com"])
-      %Mail.Message{headers: %{bcc: ["one@example.com", "two@example.com"]}}
+      iex> Mail.put_bcc(%Mail.Message{}, ["one@example.com", "two@example.com"])
+      %Mail.Message{headers: %{"bcc" => ["one@example.com", "two@example.com"]}}
 
-      Mail.put_bcc(%Mail.Message{}, "one@example.com")
-      |> Mail.put_bcc(["two@example.com", "three@example.com"])
-      %Mail.Message{headers: %{bcc: ["one@example.com", "two@example.com", "three@example.com"]}}
+      iex> Mail.put_bcc(%Mail.Message{}, "one@example.com")
+      iex> |> Mail.put_bcc(["two@example.com", "three@example.com"])
+      %Mail.Message{headers: %{"bcc" => ["one@example.com", "two@example.com", "three@example.com"]}}
 
   The value of a recipient must conform to either a string value or a tuple with two elements,
   otherwise an `ArgumentError` is raised.
@@ -396,8 +401,10 @@ defmodule Mail do
   @doc """
   Add a new `from` header
 
-      Mail.put_from(%Mail.Message{}, "user@example.com")
-      %Mail.Message{headers: %{from: "user@example.com"}}
+  ## Examples
+
+      iex> Mail.put_from(%Mail.Message{}, "user@example.com")
+      %Mail.Message{headers: %{"from" => "user@example.com"}}
   """
   def put_from(message, sender),
     do: Mail.Message.put_header(message, "from", sender)
@@ -411,8 +418,10 @@ defmodule Mail do
   @doc """
   Add a new `reply-to` header
 
-      Mail.put_reply_to(%Mail.Message{}, "user@example.com")
-      %Mail.Message{headers: %{reply_to: "user@example.com"}}
+  ## Examples
+
+      iex> Mail.put_reply_to(%Mail.Message{}, "user@example.com")
+      %Mail.Message{headers: %{"reply-to" => "user@example.com"}}
   """
   def put_reply_to(message, reply_address),
     do: Mail.Message.put_header(message, "reply-to", reply_address)
diff --git a/lib/mail/message.ex b/lib/mail/message.ex
index a6d707b..59ec8a8 100644
--- a/lib/mail/message.ex
+++ b/lib/mail/message.ex
@@ -9,7 +9,10 @@ defmodule Mail.Message do
   @doc """
   Add new part
 
-      Mail.Message.put_part(%Mail.Message{}, %Mail.Message{})
+  ## Examples
+
+      iex> Mail.Message.put_part(%Mail.Message{}, %Mail.Message{})
+      %Mail.Message{parts: [%Mail.Message{}]}
   """
   def put_part(message, %Mail.Message{} = part) do
     put_in(message.parts, message.parts ++ [part])
@@ -27,10 +30,14 @@ defmodule Mail.Message do
   @doc """
   Will match on a full or partial content type
 
-      Mail.Message.match_content_type?(message, ~r/text/)
+  ## Examples
+
+      iex> message = %Mail.Message{headers: %{"content-type" => ["text/plain", {"charset", "UTF-8"}]}}
+      iex> Mail.Message.match_content_type?(message, ~r/text/)
       true
 
-      Mail.Message.match_content_type?(message, "text/html")
+      iex> message = %Mail.Message{headers: %{"content-type" => ["text/plain", {"charset", "UTF-8"}]}}
+      iex> Mail.Message.match_content_type?(message, "text/html")
       false
   """
   def match_content_type?(message, string_or_regex)
@@ -52,7 +59,10 @@ defmodule Mail.Message do
   @doc """
   Add a new header key/value pair
 
-      Mail.Message.put_header(%Mail.Message{}, :content_type, "text/plain")
+  ## Examples
+
+      iex> Mail.Message.put_header(%Mail.Message{}, :content_type, "text/plain")
+      %Mail.Message{headers: %{"content-type" => "text/plain"}}
 
   The individual headers will be in the `headers` field on the
   `%Mail.Message{}` struct
@@ -72,7 +82,9 @@ defmodule Mail.Message do
   @doc """
   Deletes a specific header key
 
-      Mail.Message.delete_header(%Mail.Message{headers: %{foo: "bar"}}, :foo)
+  ## Examples
+
+      iex> Mail.Message.delete_header(%Mail.Message{headers: %{"foo" => "bar"}}, :foo)
       %Mail.Message{headers: %{}}
   """
   def delete_header(message, header),
@@ -81,7 +93,9 @@ defmodule Mail.Message do
   @doc """
   Deletes a list of headers
 
-      Mail.Message.delete_headers(%Mail.Message{headers: %{foo: "bar", baz: "qux"}}, [:foo, :baz])
+  ## Examples
+
+      iex> Mail.Message.delete_headers(%Mail.Message{headers: %{"foo" => "bar", "baz" => "qux"}}, [:foo, :baz])
       %Mail.Message{headers: %{}}
   """
   def delete_headers(message, headers)
@@ -104,24 +118,35 @@ defmodule Mail.Message do
 
   The value will always be wrapped in a `List`
 
-      Mail.Message.put_content_type(%Mail.Message{}, "text/plain")
-      %Mail.Message{headers: %{content_type: ["text/plain"]}}
+  ## Examples
+
+      iex> Mail.Message.put_content_type(%Mail.Message{}, "text/plain")
+      %Mail.Message{headers: %{"content-type" => ["text/plain"]}}
+
+      iex> Mail.Message.put_content_type(%Mail.Message{}, ["text/plain", {"charset", "UTF-8"}])
+      %Mail.Message{headers: %{"content-type" => ["text/plain", {"charset", "UTF-8"}]}}
   """
-  def put_content_type(message, content_type),
-    do: put_header(message, :content_type, content_type)
+  def put_content_type(message, content_type) when is_binary(content_type),
+    do: put_content_type(message, [content_type])
+
+  def put_content_type(message, content_type) do
+    put_header(message, :content_type, content_type)
+  end
 
   @doc """
   Gets the `content_type` from the header
 
   Will ensure the `content_type` is always wrapped in a `List`
 
-      Mail.Message.get_content_type(%Mail.Message{})
+  ## Examples
+
+      iex> Mail.Message.get_content_type(%Mail.Message{})
       [""]
 
-      Mail.Message.get_content_type(%Mail.Message{content_type: "text/plain"})
+      iex> Mail.Message.get_content_type(%Mail.Message{headers: %{"content-type" => "text/plain"}})
       ["text/plain"]
 
-      Mail.Message.get_content_type(%Mail.Message{headers: %{content_type: ["multipart/mixed", {"boundary", "foobar"}]}})
+      iex> Mail.Message.get_content_type(%Mail.Message{headers: %{"content-type" => ["multipart/mixed", {"boundary", "foobar"}]}})
       ["multipart/mixed", {"boundary", "foobar"}]
   """
   def get_content_type(message),
@@ -135,11 +160,13 @@ defmodule Mail.Message do
   Will overwrite existing `boundary` key in the list. Will preserve other
   values in the list
 
-      Mail.Message.put_boundary(%Mail.Message{}, "foobar")
-      %Mail.Message{headers: %{content_type: ["", {"boundary", "foobar"}]}}
+  ## Examples
+
+      iex> Mail.Message.put_boundary(%Mail.Message{}, "foobar")
+      %Mail.Message{headers: %{"content-type" => ["", {"boundary", "foobar"}]}}
 
-      Mail.Message.put_boundary(%Mail.Message{headers: %{content_type: ["multipart/mixed", {"boundary", "bazqux"}]}})
-      %Mail.Message{headers: %{content_type: ["multipart/mixed", {"boundary", "foobar"}]}}
+      iex> Mail.Message.put_boundary(%Mail.Message{headers: %{"content-type" => ["multipart/mixed", {"boundary", "bazqux"}]}}, "foobar")
+      %Mail.Message{headers: %{"content-type" => ["multipart/mixed", {"boundary", "foobar"}]}}
   """
   def put_boundary(message, boundary) do
     content_type =
@@ -154,10 +181,12 @@ defmodule Mail.Message do
 
   Will retrieve the boundary value. If one is not set a random one is generated.
 
-      Mail.Message.get_boundary(%Mail.Message{headers: %{content_type: ["multipart/mixed", {"boundary", "foobar"}]}})
+  ## Examples
+
+      iex> Mail.Message.get_boundary(%Mail.Message{headers: %{"content-type" => ["multipart/mixed", {"boundary", "foobar"}]}})
       "foobar"
 
-      Mail.Message.get_boundary(%Mail.Message{headers: %{content_type: ["multipart/mixed"]}})
+      iex> Mail.Message.get_boundary(%Mail.Message{headers: %{"content-type" => ["multipart/mixed", {"boundary", "ASDFSHNEW3473423"}]}})
       "ASDFSHNEW3473423"
   """
   def get_boundary(message) do
@@ -177,7 +206,9 @@ defmodule Mail.Message do
   @doc """
   Sets the `body` field on the part
 
-      Mail.Message.put_body(%Mail.Message{}, "Some data")
+  ## Examples
+
+      iex> Mail.Message.put_body(%Mail.Message{}, "Some Data")
       %Mail.Message{body: "Some Data", headers: %{}}
   """
   def put_body(part, body),
@@ -186,11 +217,13 @@ defmodule Mail.Message do
   @doc """
   Build a new text message
 
-      Mail.Message.build_text("Some text")
-      %Mail.Message{body: "Some text", headers: %{content_type: "text/plain"}}
+  ## Examples
 
-      Mail.Message.build_text("Some text", charset: "UTF-8")
-      %Mail.Message{body: "Some text", headers: %{content_type: ["text/plain", {"charset", "UTF-8"}]}}
+      iex> Mail.Message.build_text("Some text")
+      %Mail.Message{body: "Some text", headers: %{"content-type" => ["text/plain", {"charset", "UTF-8"}], "content-transfer-encoding" => :quoted_printable}}
+
+      iex> Mail.Message.build_text("Some text", charset: "us-ascii")
+      %Mail.Message{body: "Some text", headers: %{"content-type" => ["text/plain", {"charset", "us-ascii"}], "content-transfer-encoding" => :quoted_printable}}
 
   ## Options
 
@@ -214,11 +247,13 @@ defmodule Mail.Message do
   @doc """
   Build a new HTML message
 
-      Mail.Message.build_html("<h1>Some HTML</h1>")
-      %Mail.Message{body: "<h1>Some HTML</h1>", headers: %{content_type: "text/html"}}
+  ## Examples
+
+      iex> Mail.Message.build_html("<h1>Some HTML</h1>")
+      %Mail.Message{body: "<h1>Some HTML</h1>", headers: %{"content-type" => ["text/html", {"charset", "UTF-8"}], "content-transfer-encoding" => :quoted_printable}}
 
-      Mail.Message.build_html("<h1>Some HTML</h1>", charset: "UTF-8")
-      %Mail.Message{body: "<h1>Some HTML</h1>", headers: %{content_type: ["text/html", {"charset", "UTF-8"}]}}
+      iex> Mail.Message.build_html("<h1>Some HTML</h1>", charset: "UTF-8")
+      %Mail.Message{body: "<h1>Some HTML</h1>", headers: %{"content-type" => ["text/html", {"charset", "UTF-8"}], "content-transfer-encoding" => :quoted_printable}}
 
   ## Options
 
@@ -255,11 +290,13 @@ defmodule Mail.Message do
 
   The mimetype of the file is determined by the file extension.
 
-      Mail.Message.build_attachment("README.md")
-      %Mail.Message{data: "base64 encoded", headers: %{content_type: ["text/x-markdown"], content_disposition: ["attachment", filename: "README.md"], content_transfer_encoding: :base64}}
+  ## Examples
 
-      Mail.Message.build_attachment({"README.md", "file contents"})
-      %Mail.Message{data: "base64 encoded", headers: %{content_type: ["text/x-markdown"], content_disposition: ["attachment", filename: "README.md"], content_transfer_encoding: :base64}}
+      iex> message = Mail.Message.build_attachment("README.md")
+      %Mail.Message{body: <<"# Mail\\n", _::binary>>, headers: %{"content-type" => ["text/markdown"], "content-disposition" => ["attachment", {"filename", "README.md"}], "content-transfer-encoding" => :base64}} = message
+
+      iex> message = Mail.Message.build_attachment({"README.md", "file contents"})
+      %Mail.Message{body: "file contents", headers: %{"content-type" => ["text/markdown"], "content-disposition" => ["attachment", {"filename", "README.md"}], "content-transfer-encoding" => :base64}} = message
 
   ## Options
 
@@ -297,18 +334,20 @@ defmodule Mail.Message do
     * `:headers` - Headers to be merged
 
   ## Examples
-      Mail.Message.put_attachment(%Mail.Message{}, "README.md")
-      %Mail.Message{data: "base64 encoded", headers: %{content_type: ["text/x-markdown"], content_disposition: ["attachment", filename: "README.md"], content_transfer_encoding: :base64}}
 
-      Mail.Message.put_attachment(%Mail.Message{}, {"README.md", "file contents"})
-      %Mail.Message{data: "base64 encoded", headers: %{content_type: ["text/x-markdown"], content_disposition: ["attachment", filename: "README.md"], content_transfer_encoding: :base64}}
+      iex> message = Mail.Message.put_attachment(%Mail.Message{}, "README.md")
+      %Mail.Message{body: <<"# Mail\\n", _::binary>>, headers: %{"content-type" => ["text/markdown"], "content-disposition" => ["attachment", {"filename", "README.md"}], "content-transfer-encoding" => :base64}} = message
+
+      iex> Mail.Message.put_attachment(%Mail.Message{}, {"README.md", "file contents"})
+      %Mail.Message{body: "file contents", headers: %{"content-type" => ["text/markdown"], "content-disposition" => ["attachment", {"filename", "README.md"}], "content-transfer-encoding" => :base64}}
 
   ### Adding custom headers
-      Mail.Message.put_attachment(%Mail.Message{}, "README.md", headers: [content_id: "attachment-id"])
-      %Mail.Message{data: "base64 encoded", headers: %{content_type: ["text/x-markdown"], content_disposition: ["attachment", filename: "README.md"], content_transfer_encoding: :base64, content_id: "attachment-id"}}
 
-      Mail.Message.put_attachment(%Mail.Message{}, {"README.md", data}, headers: [content_id: "attachment-id"])
-      %Mail.Message{data: "base64 encoded", headers: %{content_type: ["text/x-markdown"], content_disposition: ["attachment", filename: "README.md"], content_transfer_encoding: :base64, content_id: "attachment-id"}}
+      iex> message =Mail.Message.put_attachment(%Mail.Message{}, "README.md", headers: [content_id: "attachment-id"])
+      %Mail.Message{body: <<"# Mail\\n", _::binary>>, headers: %{"content-type" => ["text/markdown"], "content-disposition" => ["attachment", {"filename", "README.md"}], "content-transfer-encoding" => :base64, "content-id" => "attachment-id"}} = message
+
+      iex> message = Mail.Message.put_attachment(%Mail.Message{}, {"README.md", "file contents"}, headers: [content_id: "attachment-id"])
+      %Mail.Message{body: "file contents", headers: %{"content-type" => ["text/markdown"], "content-disposition" => ["attachment", {"filename", "README.md"}], "content-transfer-encoding" => :base64, "content-id" => "attachment-id"}} = message
   """
   def put_attachment(message, path_or_file_tuple, opts \\ [])
 
diff --git a/lib/mail/parsers/rfc_2822.ex b/lib/mail/parsers/rfc_2822.ex
index e3c1c80..92566f6 100644
--- a/lib/mail/parsers/rfc_2822.ex
+++ b/lib/mail/parsers/rfc_2822.ex
@@ -1,12 +1,24 @@
 defmodule Mail.Parsers.RFC2822 do
-  @moduledoc """
+  @moduledoc ~S"""
   RFC2822 Parser
 
   Will attempt to parse a valid RFC2822 message back into
   a `%Mail.Message{}` data model.
 
-      Mail.Parsers.RFC2822.parse(message)
-      %Mail.Message{body: "Some message", headers: %{to: ["user@example.com"], from: "other@example.com", subject: "Read this!"}}
+  ## Examples
+
+      iex> message = \"""
+      ...> To: user@example.com\r
+      ...> From: me@example.com\r
+      ...> Subject: Test Email\r
+      ...> Content-Type: text/plain; foo=bar;\r
+      ...>   baz=qux;\r
+      ...> \r
+      ...> This is the body!\r
+      ...> It has more than one line\r
+      ...> \"""
+      iex> Mail.Parsers.RFC2822.parse(message)
+      %Mail.Message{body: "This is the body!\r\nIt has more than one line", headers: %{"to" => ["user@example.com"], "from" => "me@example.com", "subject" => "Test Email", "content-type" => ["text/plain", {"foo", "bar"}, {"baz", "qux"}]}}
   """
 
   @months ~w(jan feb mar apr may jun jul aug sep oct nov dec)
@@ -204,16 +216,6 @@ defmodule Mail.Parsers.RFC2822 do
 
   def to_datetime(invalid_datetime), do: {:error, invalid_datetime}
 
-  # # Fixes invalid value: Wed, 14 10 2015 12:34:17
-  # def to_datetime(
-  #       <<date::binary-size(2), " ", month_digits::binary-size(2), " ", year::binary-size(4), " ",
-  #         hour::binary-size(2), ":", minute::binary-size(2), ":", second::binary-size(2),
-  #         rest::binary>>
-  #     ) do
-  #   month_name = get_month_name(month_digits)
-  #   to_datetime("#{date} #{month_name} #{year} #{hour}:#{minute}:#{second}#{rest}")
-  # end
-
   defp to_four_digit_year(year) when year >= 0 and year < 50, do: 2000 + year
   defp to_four_digit_year(year) when year < 100 and year >= 50, do: 1900 + year
 
diff --git a/test/mail/message_test.exs b/test/mail/message_test.exs
index 9b33da8..5b8dfe0 100644
--- a/test/mail/message_test.exs
+++ b/test/mail/message_test.exs
@@ -1,5 +1,6 @@
 defmodule Mail.MessageTest do
   use ExUnit.Case, async: true
+  doctest Mail.Message
 
   test "put_part" do
     part = %Mail.Message{body: "new part"}
@@ -51,7 +52,7 @@ defmodule Mail.MessageTest do
 
   test "put_content_type" do
     message = Mail.Message.put_content_type(%Mail.Message{}, "multipart/mixed")
-    assert Mail.Message.get_header(message, :content_type) == "multipart/mixed"
+    assert Mail.Message.get_header(message, :content_type) == ["multipart/mixed"]
   end
 
   test "get_content_type" do
diff --git a/test/mail/parsers/rfc_2822_test.exs b/test/mail/parsers/rfc_2822_test.exs
index 05a806b..9670d8b 100644
--- a/test/mail/parsers/rfc_2822_test.exs
+++ b/test/mail/parsers/rfc_2822_test.exs
@@ -1,5 +1,6 @@
 defmodule Mail.Parsers.RFC2822Test do
   use ExUnit.Case, async: true
+  doctest Mail.Parsers.RFC2822
 
   test "parses a singlepart message" do
     message =
diff --git a/test/mail_test.exs b/test/mail_test.exs
index 046541b..53db91b 100644
--- a/test/mail_test.exs
+++ b/test/mail_test.exs
@@ -1,5 +1,6 @@
 defmodule MailTest do
   use ExUnit.Case, async: true
+  doctest Mail
 
   defmodule TestRenderer do
     def render(message) do
@@ -191,7 +192,11 @@ defmodule MailTest do
     mail =
       Mail.Message.put_part(
         Mail.build_multipart(),
-        Mail.Message.put_content_type(%Mail.Message{}, "text/plain; charset=UTF-8; format=flowed")
+        Mail.Message.put_content_type(%Mail.Message{}, [
+          "text/plain",
+          {"charset", "UTF-8"},
+          {"format", "flowed"}
+        ])
         |> Mail.Message.put_header(:content_transfer_encoding, :"8bit")
         |> Mail.Message.put_body(text)
       )