Merge pull request #17 from k1LoW/fix-no-auth

Allow defining cases where authentication is not supported

smtptest.go

@@ -60,14 +60,15 @@ func (s *Session) Logout() error {
 }
 
 func (s *Session) AuthMechanisms() []string {
+	if s.be.username == nil {
+		return nil
+	}
 	return []string{sasl.Plain}
 }
 
 func (s *Session) Auth(mech string) (sasl.Server, error) {
 	if s.be.username == nil {
-		return sasl.NewPlainServer(func(identity, username, password string) error {
-			return nil
-		}), nil
+		return nil, smtp.ErrAuthUnsupported
 	}
 	return sasl.NewPlainServer(func(identity, username, password string) error {
 		if identity != "" && identity != username {

smtptest_test.go

@@ -42,8 +42,7 @@ func TestServer(t *testing.T) {
 	})
 
 	addr := ts.Addr()
-	auth := smtp.PlainAuth("", "user@example.com", "password", ts.Host)
-	if err := smtp.SendMail(addr, auth, "sender@example.org", []string{"recipient@example.net"}, []byte(testMsg)); err != nil {
+	if err := smtp.SendMail(addr, nil, "sender@example.org", []string{"recipient@example.net"}, []byte(testMsg)); err != nil {
 		t.Fatal(err)
 	}
 
@@ -136,8 +135,7 @@ func TestServerMultipleRecipients(t *testing.T) {
 	})
 
 	addr := ts.Addr()
-	auth := smtp.PlainAuth("", "user@example.com", "password", ts.Host)
-	if err := smtp.SendMail(addr, auth, "sender@example.org", []string{"recipient@example.net", "another_recipient@example.net"}, []byte(testMsg)); err != nil {
+	if err := smtp.SendMail(addr, nil, "sender@example.org", []string{"recipient@example.net", "another_recipient@example.net"}, []byte(testMsg)); err != nil {
 		t.Fatal(err)
 	}