diff --git a/config/mail.go b/config/mail.go
index 6927dc4d..c0e6bb66 100644
--- a/config/mail.go
+++ b/config/mail.go
@@ -22,3 +22,8 @@ type Mail struct {
 func DefaultMail() Mail {
 	return Mail{}
 }
+
+// IsValid returns true if the mail configs are valid
+func (m Mail) IsValid() bool {
+	return (m.Host != "" && m.Port > 0 && m.Username != "" && m.Password != "") || m.UseCommand
+}
diff --git a/iris.go b/iris.go
index 09f24c8a..00dfcb09 100644
--- a/iris.go
+++ b/iris.go
@@ -176,7 +176,7 @@ func (s *Iris) initWebsocketServer() {
 func (s *Iris) initMailService() {
 	if s.mailService == nil {
 		// enable mail sender  service if configs are valid
-		if s.config.Mail.Host != "" && s.config.Mail.Username != "" && s.config.Mail.Password != "" {
+		if s.config.Mail.IsValid() {
 			s.mailService = mail.New(s.config.Mail)
 		}
 	}
diff --git a/mail/service.go b/mail/service.go
index 87f15369..9012cf28 100644
--- a/mail/service.go
+++ b/mail/service.go
@@ -49,8 +49,8 @@ func (m *mailer) sendSMTP(to []string, subject, body string) error {
 	defer buf.Put(buffer)
 
 	if !m.authenticated {
-		if m.config.Username == "" || m.config.Password == "" || m.config.Host == "" {
-			return fmt.Errorf("Username, Password, Host cannot be empty when using SMTP!")
+		if m.config.Username == "" || m.config.Password == "" || m.config.Host == "" || m.config.Port <= 0 {
+			return fmt.Errorf("Username, Password, Host & Port cannot be empty when using SMTP!")
 		}
 		m.auth = smtp.PlainAuth("", m.config.Username, m.config.Password, m.config.Host)
 		m.authenticated = true
@@ -75,7 +75,7 @@ func (m *mailer) sendSMTP(to []string, subject, body string) error {
 func (m *mailer) sendCmd(to []string, subject, body string) error {
 	buffer := buf.Get()
 	defer buf.Put(buffer)
-	// buffer.WriteString(body)
+
 	cmd := utils.CommandBuilder("mail", "-s", subject, strings.Join(to, ","))
 	cmd.AppendArguments("-a", "Content-type: text/html") //always html on