SMTP relay
SMTP Relay for Apps That Already Send Mail
NoticeAPI SMTP relay is for apps and frameworks that already speak SMTP. Keep your mailer configuration, use an API key as the password, and route transactional email through the same NoticeAPI logs, events, and suppressions.
import nodemailer from "nodemailer";
const transport = nodemailer.createTransport({
host: "smtp.noticeapi.com",
port: 465,
secure: true,
auth: {
user: "noticeapi",
pass: process.env.NOTICEAPI_KEY,
},
});
await transport.sendMail({
from: "Acme <[email protected]>",
to: "[email protected]",
subject: "Your receipt",
html: "<p>Thanks for your order.</p>",
});Port 465, implicit TLS
Connect to smtp.noticeapi.com on port 465 with implicit TLS, not STARTTLS.
API key authentication
Use any username and your ntc_ API key as the password. No separate SMTP credential system.
Same suppressions and quotas
SMTP mail enters the same send path, so suppressed recipients, domain readiness, and quotas still apply.
Same logs and events
Relayed mail appears in logs and delivery timelines alongside REST and SDK sends.
How it works
From test send to production traffic.
Create an API key
Use the same key format as REST: ntc_ secrets authenticate the SMTP sidecar.
Set host and port
Configure smtp.noticeapi.com, port 465, secure true, and your API key as the password.
Send from a verified domain
Production SMTP mail follows the same verified-domain rules as REST sends.
Use broadcasts for marketing
SMTP relay is transactional. Use broadcasts when unsubscribe handling and audience state matter.
Trust
SMTP without a second delivery model
SMTP is a compatibility path, not a separate product. Messages still flow through NoticeAPI sender checks, suppression rules, delivery events, logs, and the deliverability autopilot.
Implementation links
Build with the shipped docs.
FAQ
Questions developers ask before switching email.
Does SMTP support attachments?
Not in the SMTP sidecar today. Use the REST send API for attachment payloads.
Can I use SMTP for broadcasts?
Use the broadcasts API for marketing sends so unsubscribe links, audience state, and List-Unsubscribe headers are handled correctly.
Will SMTP sends show in the dashboard?
Yes. Relayed messages become normal NoticeAPI sends with logs and delivery timelines.
Start free. Send production after your domain is ready.
Free includes 3,000 production emails per month, a 100/day production cap, and one verified sending domain.