mail relay: do not accept TLS servers

haraka can only relay via STARTTLS

src/mailer.js

@@ -25,7 +25,6 @@ const assert = require('assert'),
     safe = require('safetydance'),
     settings = require('./settings.js'),
     translation = require('./translation.js'),
-    smtpTransport = require('nodemailer-smtp-transport'),
     util = require('util');
 
 const MAIL_TEMPLATES_DIR = path.join(__dirname, 'mail_templates');
@@ -52,14 +51,14 @@ async function sendMail(mailOptions) {
 
     const data = await mail.getMailAuth();
 
-    const transport = nodemailer.createTransport(smtpTransport({
+    const transport = nodemailer.createTransport({
         host: data.ip,
         port: data.port,
         auth: {
             user: mailOptions.authUser || `no-reply@${settings.dashboardDomain()}`,
             pass: data.relayToken
         }
-    }));
+    });
 
     const transportSendMail = util.promisify(transport.sendMail.bind(transport));
     const [error] = await safe(transportSendMail(mailOptions));