diff --git a/backend.go b/backend.go
index 6a00873..70881a4 100644
--- a/backend.go
+++ b/backend.go
@@ -69,7 +69,7 @@ type Session interface {
 	Logout() error
 
 	// Set return path for currently processed message.
-	Mail(from string, opts MailOptions) error
+	Mail(from string, opts *MailOptions) error
 	// Add recipient for currently processed message.
 	Rcpt(to string) error
 	// Set currently processed message contents and send it.
diff --git a/backendutil/transform.go b/backendutil/transform.go
index a5ff666..48d7cad 100755
--- a/backendutil/transform.go
+++ b/backendutil/transform.go
@@ -43,7 +43,7 @@ func (s *transformSession) Reset() {
 	s.Session.Reset()
 }
 
-func (s *transformSession) Mail(from string, opts smtp.MailOptions) error {
+func (s *transformSession) Mail(from string, opts *smtp.MailOptions) error {
 	if s.be.TransformMail != nil {
 		var err error
 		from, err = s.be.TransformMail(from)
diff --git a/backendutil/transform_test.go b/backendutil/transform_test.go
index 3c77638..d745909 100755
--- a/backendutil/transform_test.go
+++ b/backendutil/transform_test.go
@@ -63,7 +63,7 @@ func (s *session) Logout() error {
 	return nil
 }
 
-func (s *session) Mail(from string, opts smtp.MailOptions) error {
+func (s *session) Mail(from string, opts *smtp.MailOptions) error {
 	s.Reset()
 	s.msg.From = from
 	return nil
diff --git a/conn.go b/conn.go
index f033423..e925306 100644
--- a/conn.go
+++ b/conn.go
@@ -331,7 +331,7 @@ func (c *Conn) handleMail(arg string) {
 	}
 	from = strings.Trim(from, "<>")
 
-	opts := MailOptions{}
+	opts := &MailOptions{}
 
 	c.binarymime = false
 	// This is where the Conn may put BODY=8BITMIME, but we already
diff --git a/example_test.go b/example_test.go
index 607c971..6665a3c 100644
--- a/example_test.go
+++ b/example_test.go
@@ -108,7 +108,7 @@ func (bkd *Backend) AnonymousLogin(state *smtp.ConnectionState) (smtp.Session, e
 // A Session is returned after successful login.
 type Session struct{}
 
-func (s *Session) Mail(from string, opts smtp.MailOptions) error {
+func (s *Session) Mail(from string, opts *smtp.MailOptions) error {
 	log.Println("Mail from:", from)
 	return nil
 }
diff --git a/server_test.go b/server_test.go
index f2bfe9f..d3a977c 100644
--- a/server_test.go
+++ b/server_test.go
@@ -17,7 +17,7 @@ type message struct {
 	From string
 	To   []string
 	Data []byte
-	Opts smtp.MailOptions
+	Opts *smtp.MailOptions
 }
 
 type backend struct {
@@ -91,7 +91,7 @@ func (s *session) Logout() error {
 	return nil
 }
 
-func (s *session) Mail(from string, opts smtp.MailOptions) error {
+func (s *session) Mail(from string, opts *smtp.MailOptions) error {
 	if s.backend.panicOnMail {
 		panic("Everything is on fire!")
 	}