diff --git a/mail/message.go b/mail/message.go
index 7c9295e..fd807cc 100644
--- a/mail/message.go
+++ b/mail/message.go
@@ -15,6 +15,7 @@ type Message struct {
 	CC      []string
 	Bcc     []string
 	Subject string
+	Headers map[string]string
 
 	Bodies      []Body
 	Attachments []Attachment
@@ -76,7 +77,12 @@ func (m *Message) AddAttachment(name, contentType string, r io.Reader) error {
 	return nil
 }
 
+// SetHeader sets the heder field and value for the message
+func (m *Message) SetHeader(field, value string) {
+	m.Headers[field] = value
+}
+
 //NewMessage Builds a new message.
 func NewMessage() Message {
-	return Message{}
+	return Message{Headers: map[string]string{}}
 }
diff --git a/mail/smtp_sender.go b/mail/smtp_sender.go
index 987a411..50f8a4f 100644
--- a/mail/smtp_sender.go
+++ b/mail/smtp_sender.go
@@ -47,6 +47,10 @@ func (sm SMTPSender) Send(message Message) error {
 		m.Attach(at.Name, settings)
 	}
 
+	for field, value := range message.Headers {
+		m.SetHeader(field, value)
+	}
+
 	err := sm.Dialer.DialAndSend(m)
 
 	if err != nil {
diff --git a/mail/smtp_sender_test.go b/mail/smtp_sender_test.go
index 9521db9..46bf05b 100644
--- a/mail/smtp_sender_test.go
+++ b/mail/smtp_sender_test.go
@@ -28,18 +28,19 @@ func TestSendPlain(t *testing.T) {
 	smtpServer.Clear()
 	r := require.New(t)
 
-	m := mail.Message{
-		From:    "mark@example.com",
-		To:      []string{"something@something.com"},
-		Subject: "Cool Message",
-		CC:      []string{"other@other.com", "my@other.com"},
-		Bcc:     []string{"secret@other.com"},
-	}
+	m := mail.NewMessage()
+	m.From = "mark@example.com"
+	m.To = []string{"something@something.com"}
+	m.Subject = "Cool Message"
+	m.CC = []string{"other@other.com", "my@other.com"}
+	m.Bcc = []string{"secret@other.com"}
 
 	m.AddAttachment("someFile.txt", "text/plain", bytes.NewBuffer([]byte("hello")))
 	m.AddBody(rend.String("Hello <%= Name %>"), render.Data{"Name": "Antonio"})
 	r.Equal(m.Bodies[0].Content, "Hello Antonio")
 
+	m.SetHeader("X-SMTPAPI", `{"send_at": 1409348513}`)
+
 	err := sender.Send(m)
 	r.Nil(err)
 
@@ -55,4 +56,5 @@ func TestSendPlain(t *testing.T) {
 	r.Contains(lastMessage, "Hello Antonio")
 	r.Contains(lastMessage, "Content-Disposition: attachment; filename=\"someFile.txt\"")
 	r.Contains(lastMessage, "aGVsbG8=") //base64 of the file content
+	r.Contains(lastMessage, `X-SMTPAPI: {"send_at": 1409348513}`)
 }