SMTP relay

The Emailit SMTP relay accepts mail from anything that can send over SMTP, such as a CMS, a framework’s mailer, a monitoring tool or a scanner, and delivers it through the same pipeline as the Email API. Use it when changing SMTP settings is easier than writing API code.

When to use SMTP

SMTP is a good fit when:

• Your software only supports SMTP, like WordPress plugins, help desks and network devices.
• You’re moving from another provider and want to change only the host and credentials.
• Your framework already has an SMTP mailer, as Laravel, Django, Rails and Nodemailer do.

Choose the API when you need templates with variables, scheduling, metadata, idempotency keys or per-email tracking settings. See API or SMTP? for a full comparison.

How it works

1. Your application connects to smtp.emailit.com, upgrades the connection to TLS and logs in with an API key.
2. It sends the envelope sender, one recipient command per recipient, and the message.
3. Emailit checks the workspace, the rate limits, the message size and the domain in the From header, then replies 250 2.0.0 OK: queued as em_….
4. Each recipient becomes a separate email with its own em_ ID. Emailit signs it with DKIM, runs spam checks, delivers it and retries temporary failures, exactly as it does for API mail.

Connection details

Each API key’s page in Email API›API Keys shows the same details on its SMTP Info card. SMTP settings covers every port, the From address rules and limits.

Send a test message

cat > message.txt <<'EOF'
From: Acme <hello@acme.com>
To: ada@example.com
Subject: SMTP test from Acme

It works.
EOF

curl --url "smtp://smtp.emailit.com:587" --ssl-reqd --crlf \
  --user "emailit:$EMAILIT_API_KEY" \
  --mail-from hello@acme.com \
  --mail-rcpt ada@example.com \
  --upload-file message.txt -v

import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  host: 'smtp.emailit.com',
  port: 587,
  secure: false, // STARTTLS on 587
  requireTLS: true,
  auth: { user: 'emailit', pass: process.env.EMAILIT_API_KEY },
});

const info = await transporter.sendMail({
  from: 'Acme <hello@acme.com>',
  to: 'ada@example.com',
  subject: 'SMTP test from Acme',
  text: 'It works.',
});

console.log(info.response); // 250 2.0.0 OK: queued as em_…

import os
import smtplib
from email.message import EmailMessage

msg = EmailMessage()
msg["From"] = "Acme <hello@acme.com>"
msg["To"] = "ada@example.com"
msg["Subject"] = "SMTP test from Acme"
msg.set_content("It works.")

with smtplib.SMTP("smtp.emailit.com", 587) as smtp:
    smtp.starttls()
    smtp.login("emailit", os.environ["EMAILIT_API_KEY"])
    smtp.send_message(msg)

use PHPMailer\PHPMailer\PHPMailer;

$mail = new PHPMailer(true);
$mail->isSMTP();
$mail->Host = 'smtp.emailit.com';
$mail->Port = 587;
$mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
$mail->SMTPAuth = true;
$mail->Username = 'emailit';
$mail->Password = getenv('EMAILIT_API_KEY');

$mail->setFrom('hello@acme.com', 'Acme');
$mail->addAddress('ada@example.com');
$mail->Subject = 'SMTP test from Acme';
$mail->Body = 'It works.';
$mail->send();

New workspaces are in sandbox mode and can only send to workspace members’ account emails. Request production access before you send to anyone else.

How SMTP mail appears in Emailit

• One email per recipient. A message with three recipients creates three emails, each with its own em_ ID, status and events.
• IDs in the reply. The 250 reply after the message lists the new IDs, for example 250 2.0.0 OK: queued as em_33VtK8mRq1xZp7LwN4cY2bHsDfa. They’re the same IDs the API, dashboard and webhooks use. See SMTP headers and replies.
• Emails list. The emails appear in Email API›Emails. Filter by API key to see one application’s mail.
• Logs. Each submitted message appears in Email API›Logs with the source SMTP and its reply code, together with rate-limit rejections and failed logins. See Request logs.
• Webhooks. SMTP mail emits the same delivery and engagement events as API mail, but not email.accepted. The first event is usually email.delivered.

How SMTP differs from the Email API

Emailit doesn’t read X-Emailit-* control headers in SMTP messages. See SMTP headers.

Limits

Pro and Business workspaces get automatic limit increases based on sending health, and any workspace can request more from the Sending Limits card on the dashboard home page. See Limits.

Next steps