Spf dkim dmarc check — check email sending setup and dns records

Checks mail-sending code and DNS records against the Gmail/Yahoo bulk sender rules and Microsoft Outlook.com's: SPF, DKIM, DMARC, RFC 8058 one-click unsubscribe, TLS - each with the date it took effect. Runs entirely in your browser — nothing is uploaded.

// mail/digest.js - nightly product digest, ~42,000 recipients (mostly gmail.com and outlook.com)
'use strict';
const nodemailer = require('nodemailer');
const app = require('../app');
const { requireAuth } = require('../auth');

// DNS for the sending domain - paste into Route 53 when the new sender goes live
const DNS = {
  spf:   'v=spf1 include:_spf.google.com include:sendgrid.net include:mailgun.org include:amazonses.com include:servers.mcsv.net include:spf.protection.outlook.com include:_spf.salesforce.com include:mail.zendesk.com include:shops.shopify.com include:stspg-customer.com include:helpscout.net ?all',
  dkim:  'v=DKIM1; k=rsa; t=y; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7Kd1JqTn4fY2mQ0Z',
  dmarc: 'v=DMARC1; p=none; pct=20; sp=none',
  bimi:  'v=BIMI1; l=https://cdn.acme.example/logo.svg;'
};

const transport = nodemailer.createTransport({
  host: 'smtp.acme.example', port: 25, secure: false, tls: { rejectUnauthorized: false },
  auth: { user: process.env.SMTP_USER, pass: process.env.SMTP_PASS }
});

async function sendDigest(recipients, html) {
  for (const to of recipients) {
    await transport.sendMail({
      from: 'Acme Digest <acme.digest@gmail.com>',
      to,
      subject: 'Your weekly Acme digest',
      html,
      headers: { 'List-Unsubscribe': '<mailto:unsub@acme.example>' }
    });
  }
}

app.get('/unsubscribe', requireAuth, (req, res) => res.render('unsubscribe', { user: req.user }));

module.exports = { sendDigest, DNS };

as of

Free here: Check the file you have open - every check, with the rule it comes from, the date it took effect and the line. In the editor: Sweep every file in the workspace and write a dated evidence report you keep - $29 once, one licence key per person or team seat; a deliverability consultant bills $150-$250 an hour — that part asks for a licence key.

Same engine as the VS Code extension, byte for byte.