How to Use Our SMTP Relay in Your App or Website

If your app, website, or script needs to send emails (password resets, order confirmations, contact form submissions) without running your own full mail server, our SMTP relay plans are built exactly for that.

What SMTP Relay Actually Is

Instead of receiving mail, a relay account is purely for sending, authenticated with a username and password, through our mail infrastructure. Your app connects like it would to any SMTP provider (Gmail SMTP, SendGrid, etc.) — this is the same integration pattern, just pointed at our servers.

What You Need

From your relay service's management page:

• SMTP hostname
• Port (usually 587 for STARTTLS, or 465 for implicit SSL/TLS — check which your relay service page specifies)
• Username and password
• The "from" address you're authorized to send as

Connecting From Common Platforms

• WordPress (via an SMTP plugin like WP Mail SMTP): enter the host, port, and credentials in the plugin's settings, select TLS/SSL to match your port, and send a test email.
• PHP (PHPMailer or similar): set Host, Port, SMTPAuth = true, Username, Password, and SMTPSecure (tls or ssl) to match your relay's settings.
• Node.js (Nodemailer): create a transport with host, port, secure (true for 465, false for 587 with STARTTLS), and auth: { user, pass }.
• Python (smtplib): connect to the host/port, call starttls() if using port 587, then login(user, password) before sending.

The pattern is identical across platforms: host, port, username, password, and whether you're using implicit TLS or STARTTLS.

Rate Limits

Relay accounts carry a sending rate limit (how many emails per hour/day you can send) — this exists to protect the shared sending reputation of the relay infrastructure for every customer using it, not just you. If you're hitting the limit regularly, a higher relay tier raises it — check your plan's page for the exact number.

Deliverability: The Part That Actually Matters

Getting the SMTP connection working is the easy part. Whether your emails land in an inbox instead of spam depends heavily on SPF, DKIM, and DMARC being set up correctly for the domain you're sending from — see our full explainer. If you're sending from your own custom domain through our relay, this step is not optional.

Testing It

Before wiring it into production, send a manual test email using the same credentials via a simple script or your platform's built-in test-email feature. Confirm it actually arrives (check spam too) before relying on it for real transactional mail like password resets, where a delivery failure has real consequences for your users.