diff --git a/dkim.go b/dkim.go
index ec6fa85..0159519 100644
--- a/dkim.go
+++ b/dkim.go
@@ -2,6 +2,7 @@ package dkim
 
 import (
 	"bytes"
+	"io/ioutil"
 	"strings"
 	"time"
 )
@@ -88,6 +89,9 @@ func Sign(email *bytes.Reader, options sigOptions) (*bytes.Reader, error) {
 	if len(p) > 2 {
 		return nil, ErrSignBadCanonicalization
 	}
+	if len(p) == 1 {
+		options.Canonicalization = options.Canonicalization + "/simple"
+	}
 	for _, c := range p {
 		if c != "simple" && c != "relaxed" {
 			return nil, ErrSignBadCanonicalization
@@ -104,7 +108,8 @@ func Sign(email *bytes.Reader, options sigOptions) (*bytes.Reader, error) {
 	// normalize -> strtlower
 	hasFrom := false
 	for i, h := range options.Headers {
-		options.Headers[i] = strings.ToLower(h)
+		h = strings.ToLower(h)
+		options.Headers[i] = h
 		if h == "from" {
 			hasFrom = true
 		}
@@ -113,7 +118,39 @@ func Sign(email *bytes.Reader, options sigOptions) (*bytes.Reader, error) {
 		return nil, ErrSignHeaderShouldContainsFrom
 	}
 
-	//
+	// Normalize
+	//normalizedHeaders, NormalizedBody, err := normalize(email, options)
+
+	canonicalize(email, options)
 
 	return nil, nil
 }
+
+func canonicalize(emailReader *bytes.Reader, options sigOptions) (headers, body []byte, err error) {
+	var email []byte
+	email, err = ioutil.ReadAll(emailReader)
+	emailReader.Seek(0, 0)
+	if err != nil {
+		return
+	}
+
+	parts := bytes.SplitN(email, []byte{13, 10, 13, 10}, 2)
+
+	canonicalizations := strings.Split(options.Canonicalization, "/")
+	// canonicalyze body
+	if canonicalizations[1] == "simple" {
+		body = bytes.TrimRight(parts[1], "\r\n")
+		body = append(body, []byte{13, 10}...)
+	} else {
+		for _, line := range bytes.Split(parts[1], []byte{10}) {
+			println(line)
+		}
+	}
+
+	println(string(parts[0]))
+	println("\r\n")
+	println(string(parts[1]))
+	println(string(body))
+
+	return
+}
diff --git a/dkim_test.go b/dkim_test.go
index 7b0196e..4df6fc2 100644
--- a/dkim_test.go
+++ b/dkim_test.go
@@ -6,20 +6,42 @@ import (
 	"testing"
 )
 
+const (
+	privKey = `MIICXQIBAAKBgQDNUXO+Qsl1tw+GjrqFajz0ERSEUs1FHSL/+udZRWn1Atw8gz0+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`
+
+	pubKey = `MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDNUXO+Qsl1tw+GjrqFajz0ERSE
+Us1FHSL/+udZRWn1Atw8gz0+tcGqhWChBDeU9gY5sKLEAZnX3FjC/T/IbqeiSM68
+kS5vLkzRI84eiJrm3+IieUqIIicsO+WYxQs+JgVx5XhpPjX4SQjHtwEC2xKkWnEv
++VPgO1JWdooURcSC6QIDAQAB`
+
+	domain = "tmail.io"
+
+	selector = "test"
+)
+
 var email = `Received: (qmail 28277 invoked from network); 1 May 2015 09:43:37 -0000
 Received: (qmail 21323 invoked from network); 1 May 2015 09:48:39 -0000
 MIME-Version: 1.0
 Date: Fri, 1 May 2015 11:48:37 +0200
 Message-ID: <CADu37kTXBeNkJdXc4bSF8DbJnXmNjkLbnswK6GzG_2yn7U7P6w@tmail.io>
 Subject: Test DKIM
-From: =?UTF-8?Q?St=C3=A9phane_Depierrepont?= <toorop@gmail.com>
+From: =?UTF-8?Q?St=C3=A9phane_Depierrepont?= <toorop@tmail.io>
 To: =?UTF-8?Q?St=C3=A9phane_Depierrepont?= <toorop@toorop.fr>
-Content-Type: text/plain; charset=UTF-8
-
-
-Hello world
+Content-Type: text/plain; charset=UTF-8` + "\r\n\r\n" + `Hello world
 -- 
-Toorop`
+Toorop` + "\r\n\r\n\r\n\r\n\r\n\r\n\r\n"
 
 func Test_NewSigOptions(t *testing.T) {
 	options := NewSigOptions()
@@ -66,8 +88,22 @@ func Test_SignConfig(t *testing.T) {
 	assert.NoError(t, err)
 
 	// header
-	/*options.Headers = []string{"toto"}
+	options.Headers = []string{"toto"}
 	_, err = Sign(emailReader, options)
-	assert.EqualError(t, err, ErrSignHeaderShouldContainsFrom.Error())*/
+	assert.EqualError(t, err, ErrSignHeaderShouldContainsFrom.Error())
 
+	options.Headers = []string{"To", "From"}
+	_, err = Sign(emailReader, options)
+	assert.NoError(t, err)
+}
+
+func Test_Sign(t *testing.T) {
+	emailReader := bytes.NewReader([]byte(email))
+	options := NewSigOptions()
+	options.PrivateKey = privKey
+	options.Canonicalization = "simple/relaxed"
+	options.Domain = domain
+	options.Selector = selector
+	emailReader, err := Sign(emailReader, options)
+	assert.NoError(t, err)
 }
diff --git a/errors.go b/errors.go
index 11f4130..640df8e 100644
--- a/errors.go
+++ b/errors.go
@@ -6,13 +6,13 @@ import (
 
 var (
 	// ErrConfigPrivateKeyRequired when there not private key in config
-	ErrSignPrivateKeyRequired = errors.New("PrivateKey is required in config")
+	ErrSignPrivateKeyRequired = errors.New("PrivateKey is required")
 
 	// ErrSignDomainRequired when there is no domain defined in config
-	ErrSignDomainRequired = errors.New("Domain is required in config")
+	ErrSignDomainRequired = errors.New("Domain is required")
 
 	// ErrSignSelectorRequired when there is no Selcteir defined in config
-	ErrSignSelectorRequired = errors.New("Selector is required in config")
+	ErrSignSelectorRequired = errors.New("Selector is required")
 
 	// If Headers is specified it should at least contain 'from'
 	ErrSignHeaderShouldContainsFrom = errors.New("Header must contains 'from' field")