Send email over SMTP — no rewrite required.
Point any SMTP app at smtp.unitpost.com. Same pipeline as the API.
Copy, paste, send
One set of credentials
Create a send-only credential. TLS is required.
| Host | smtp.unitpost.com |
|---|---|
| Username | unitpostfixed |
| Password | Your API keyneeds emails:send |
| Port 587 | STARTTLSsubmission |
| Port 465 | Implicit TLSSSL |
| Ports 2587 / 2465 | Aliasesif 587/465 blocked |
import nodemailer from "nodemailer";
const transporter = nodemailer.createTransport({
host: "smtp.unitpost.com",
port: 587, // STARTTLS
secure: false, // use port 465 + secure:true for implicit TLS
auth: {
user: "unitpost", // always "unitpost"
pass: process.env.UNITPOST_API_KEY, // your API key
},
});
await transporter.sendMail({
from: "you@yourdomain.com", // a verified domain
to: "customer@example.com",
subject: "Hello",
html: "<p>Sent via the Unitpost SMTP relay.</p>",
});Production-ready
An alternate front door, not a second-class one
SMTP isn't a bolt-on. Same send path as REST.
TLS by default
STARTTLS on 587. Implicit TLS on 465.
Same dashboard
SMTP sends log like API sends.
Webhooks
Same signed events as the API.
Idempotent retries
Unitpost-Idempotency-Key. Never double-send.
Same everything
No new mental model
API or SMTP. One gate, one set of limits, one dashboard.
Same sending gate
Verified domains, quotas, suppression. One set of rules.
Same tracking & webhooks
Same events in the dashboard. Same signed webhooks.
Same limits & idempotency
One rate limit across API and SMTP. Idempotency-Key on retries.
Questions
Common questions
What are the Unitpost SMTP settings?
Host smtp.unitpost.com, username unitpost (that literal string, not your email), and a Unitpost API key carrying emails:send as the password. Use port 587 or 2587 for STARTTLS, or 465 or 2465 for implicit TLS. TLS is mandatory. Send from any address on a domain you've verified.
Why is my username 'unitpost' and not my email address?
The relay authenticates the workspace, not a mailbox. The username is always the literal string unitpost, and the API key in the password field identifies which workspace is sending and what it's allowed to do. That means you can rotate or revoke access without touching the username, and one credential can serve every app you point at the relay.
Which SMTP port should I use?
Prefer 587 with STARTTLS — it's the standard submission port and works nearly everywhere. If your host blocks it (some cloud providers do), use 2587 for STARTTLS or 465 for implicit TLS, with 2465 as the implicit-TLS fallback. All four reach the same relay.
Do SMTP sends get tracking and webhooks?
Yes. SMTP is a second front door to the same pipeline, not a separate system. Sends go through the same verified-domain gate, quotas, and suppression checks, and they emit the same delivery, bounce, complaint, open, and click events — visible in the dashboard and delivered to your webhook endpoints.
Can I use idempotency keys over SMTP?
Yes. Set a Unitpost-Idempotency-Key MIME header on the message and it behaves exactly like the Idempotency-Key header on the REST API: a 24-hour dedupe window, so a retried delivery attempt doesn't send twice.
Point your mailer at the relay
On every plan, including free. Same tracking as the API.