Merge pull request #16 from rchakode/feat/allow-unauthenticated-smtp

Feat/allow unauthenticated smtp

app.yaml.sample

@@ -13,6 +13,7 @@ env_variables:
   TEMPLATE_CONTACT_REQUEST_REPLY: templates/template_reply_contact_request.html
   SMTP_SERVER_ADDR: "smtp.mailgun.org:587"
   SMTP_VERITY_CERT: true
+  SMTP_AUTHENTICATION_ENABLED: true
   SMTP_CLIENT_USERNAME: "postmaster@example.com"
   SMTP_CLIENT_PASSWORD: "postmasterSecretPassWord"
   CONTACT_REPLY_EMAIL: "noreply@example.com"

docs/configuration-variables.md

@@ -4,6 +4,7 @@ Regardless of the deployment platform (Google App Engine, Kubernetes, Docker), t
 
 * `SMTP_SERVER_ADDR`: Set the address of the SMTP server in the form of `host:port`. It's required that the SMTP server being supporting TLS.
 * `SMTP_VERITY_CERT`: Tell whether the SMTP certificate should be validated against top level authorities. If you're using a self-signed certificate on the SMTP server, this value must be set to `false`.
+* `SMTP_AUTHENTICATION_ENABLED`: Boolean (default: `true`) indicating whether SMTP authentication is required or not. If true, the variables `SMTP_CLIENT_USERNAME` and `SMTP_CLIENT_PASSWORD` are used the perform the authentication.
 * `SMTP_CLIENT_USERNAME`: Set the username to connect to the SMTP server.
 * `SMTP_CLIENT_PASSWORD`: Set the password to connect to the SMTP server.
 * `CONTACT_REPLY_EMAIL`: Set an email address for the reply email. It's not necessary a valid email address; for example if don't want the user to reply the email, you can set something like `noreply@example.com`.

main.go

@@ -76,6 +76,7 @@ func main() {
 	viper.SetDefault("CONTACT_REPLY_BCC_EMAIL", "contact@company.com")
 	viper.SetDefault("EMAIL_SUBJECT", "Thanks to try our product")
 	viper.SetDefault("DEMO_URL", "http://company.com/product-demo")
+	viper.SetDefault("SMTP_AUTHENTICATION_ENABLED", true)
 
 	host := os.Getenv("HOST")
 	port := os.Getenv("PORT")

sendmail.go

@@ -75,10 +75,6 @@ func (m *SendMailRequest) Execute() error {
 	// Connect to the SMTP Server
 	smtpServerAddr := viper.GetString("SMTP_SERVER_ADDR")
 	smtpServerHost, _, _ := net.SplitHostPort(smtpServerAddr)
-	smtpClientAuth := smtp.PlainAuth("",
-		viper.GetString("SMTP_CLIENT_USERNAME"),
-		viper.GetString("SMTP_CLIENT_PASSWORD"),
-		smtpServerHost)
 
 	// TLS config
 	tlsconfig := &tls.Config{
@@ -100,8 +96,15 @@ func (m *SendMailRequest) Execute() error {
 	}
 	defer smtpClient.Quit()
 
-	if err = smtpClient.Auth(smtpClientAuth); err != nil {
+	// Authenticate if configured
-		return fmt.Errorf("failed authenticating to smtp server (%s)", err)
+	if viper.GetBool("SMTP_AUTHENTICATION_ENABLED") {
+		smtpClientAuth := smtp.PlainAuth("",
+			viper.GetString("SMTP_CLIENT_USERNAME"),
+			viper.GetString("SMTP_CLIENT_PASSWORD"),
+			smtpServerHost)
+		if err = smtpClient.Auth(smtpClientAuth); err != nil {
+			return fmt.Errorf("failed authenticating to smtp server (%s)", err)
+		}
 	}
 
 	// Initialize a mail transaction