Migrate from SendGrid to RelayPost

Before you start

You'll need:

• A RelayPost account (sign up free)
• Access to your domain's DNS settings
• Access to your application code where SendGrid is integrated

The migration can be done incrementally — you don't need to switch everything at once.

Step 1: Create your RelayPost account

Sign up at app.relaypost.dev/register. Create an organization and generate an API key from the dashboard.

Step 2: Add and verify your domain

In the RelayPost dashboard, go to Domains and add your sending domain. RelayPost will provide DKIM and SPF DNS records to add. This typically takes 5 minutes to configure and under an hour for DNS propagation.

You can keep your existing SendGrid DNS records active during the transition.

Step 3: Replace API calls

SendGrid's API:

// SendGrid
const sgMail = require("@sendgrid/mail");
sgMail.setApiKey(process.env.SENDGRID_API_KEY);

await sgMail.send({
  to: "[email protected]",
  from: "[email protected]",
  subject: "Welcome",
  html: "<p>Thanks for signing up.</p>"
});

RelayPost equivalent:

// RelayPost — no SDK needed
await fetch("https://api.relaypost.dev/v1/emails/send", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_RELAYPOST_API_KEY",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    from: "[email protected]",
    to: "[email protected]",
    subject: "Welcome",
    html: "<p>Thanks for signing up.</p>"
  })
});

Step 4: Replace SMTP configuration (if using SMTP)

If you send via SMTP, update your SMTP settings:

Step 5: Update webhook endpoints

If you use SendGrid's Event Webhook, configure equivalent webhooks in RelayPost. RelayPost sends delivery, bounce, complaint, open, and click events via HTTP POST to your endpoint.

Step 6: Test and verify

Before switching production traffic:

• Send test emails to Gmail, Outlook, and Yahoo accounts
• Verify DKIM and SPF pass (check email headers)
• Confirm webhook events are received
• Check the RelayPost dashboard for delivery logs

Step 7: Switch production traffic

Once testing is complete, route production email through RelayPost. Start with non-critical emails (notifications, updates) before switching transactional email (password resets, receipts).

After confirming everything works, remove your SendGrid DNS records and revoke your SendGrid API key.

Migration checklist

• ☐ RelayPost account created
• ☐ API key generated
• ☐ Domain added and verified (DKIM/SPF passing)
• ☐ API calls updated in application code
• ☐ SMTP configuration updated (if applicable)
• ☐ Webhooks configured
• ☐ Test emails sent and verified
• ☐ Production traffic switched
• ☐ SendGrid DNS records removed
• ☐ SendGrid API key revoked

Frequently asked questions