Send via SMTP

You’re ready for your first send! Use the following details to set up your SMTP sending with the client of your choice:

Host:
Port: 587 (recommended), 25, 2525, or 465.
Username: YOUR_SMTP_USER_ID
Password: YOUR_SMTP_USER_PASSWORD

While your account is in test mode, you can only send to email addresses on domains you have verified in step #1. Select the recipient for your first test send accordingly.

Below are examples of sending via SMTP in some common languages. For testing with SMTP on the command-line, we recommend swaks.

swaks \
    --server smtp.helohq.com:587 \
    --tls \
    --from "$FROM_ADDRESS" \
    --to recipient@example.com \
    --body "<html><body><h1>Test message HTML</h1><p>Test message paragraph</p></body></html>" \
    --auth PLAIN \
    --auth-user "$SMTP_USER_ID" \
    --auth-password "$SMTP_USER_PASSWORD" \
    --add-header "X-Helo-TrackLinks: true" \
    --add-header "X-Helo-TrackOpens: true" \
    --add-header "Content-Type: text/html"

import nodemailer from "nodemailer";

const smtpUserId = process.env.SMTP_USER_ID;
const smtpPassword = process.env.SMTP_PASSWORD;
const fromAddress = process.env.FROM_ADDRESS;

const transporter = nodemailer.createTransport({
  host: "smtp.helohq.com",
  port: 587,
  secure: false,
  requireTLS: true,
  auth: {
    type: "plain",
    user: smtpUserId,
    pass: smtpPassword,
  },
});

await transporter.sendMail({
  from: fromAddress,
  to: "recipient@example.com",
  subject: "Test Message",
  html: "<html><body><h1>Test message HTML</h1><p>Test message paragraph</p></body></html>",
  text: "Test message text",
  headers: {
    "X-Helo-TrackLinks": "true",
    "X-Helo-TrackOpens": "true",
  },
});

import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

smtp_user_id = os.environ['SMTP_USER_ID']
smtp_password = os.environ['SMTP_PASSWORD']
from_address = os.environ['FROM_ADDRESS']

msg = MIMEMultipart('alternative')
msg['Subject'] = 'Test Message'
msg['From'] = from_address
msg['To'] = 'recipient@example.com'
msg['X-Helo-TrackLinks'] = 'true'
msg['X-Helo-TrackOpens'] = 'true'

msg.attach(MIMEText('Test message text', 'plain'))
msg.attach(MIMEText(
    '<html><body><h1>Test message HTML</h1><p>Test message paragraph</p></body></html>',
    'html'
))

with smtplib.SMTP('smtp.helohq.com', 587) as server:
    server.starttls()
    server.login(smtp_user_id, smtp_password)
    server.sendmail(from_address, ['recipient@example.com'], msg.as_string())

require 'net/smtp'

smtp_user_id = ENV['SMTP_USER_ID']
smtp_password = ENV['SMTP_PASSWORD']
from_address = ENV['FROM_ADDRESS']

message = <<~EMAIL
  From: #{from_address}
  To: recipient@example.com
  Subject: Test Message
  MIME-Version: 1.0
  Content-Type: text/html; charset=UTF-8
  X-Helo-TrackLinks: true
  X-Helo-TrackOpens: true

  <html><body><h1>Test message HTML</h1><p>Test message paragraph</p></body></html>
EMAIL

smtp = Net::SMTP.new('smtp.helohq.com', 587)
smtp.enable_starttls
smtp.start('localhost', smtp_user_id, smtp_password, :plain) do |conn|
  conn.send_message(message, from_address, 'recipient@example.com')
end

using System.Net;
using System.Net.Mail;

var smtpUserId = Environment.GetEnvironmentVariable("SMTP_USER_ID");
var smtpPassword = Environment.GetEnvironmentVariable("SMTP_PASSWORD");
var fromAddress = Environment.GetEnvironmentVariable("FROM_ADDRESS");

var message = new MailMessage
{
    From = new MailAddress(fromAddress),
    Subject = "Test Message",
    Body = "<html><body><h1>Test message HTML</h1><p>Test message paragraph</p></body></html>",
    IsBodyHtml = true,
};
message.To.Add("recipient@example.com");
message.Headers.Add("X-Helo-TrackLinks", "true");
message.Headers.Add("X-Helo-TrackOpens", "true");

using var client = new SmtpClient("smtp.helohq.com", 587)
{
    Credentials = new NetworkCredential(smtpUserId, smtpPassword),
    EnableSsl = true,
};
client.Send(message);

package main

import (
	"fmt"
	"net/smtp"
	"os"
	"strings"
)

func main() {
	host := "smtp.helohq.com"
	addr := fmt.Sprintf("%s:%d", host, 587)

	smtpUserId := os.Getenv("SMTP_USER_ID")
	smtpPassword := os.Getenv("SMTP_PASSWORD")
	fromAddress := os.Getenv("FROM_ADDRESS")

	auth := smtp.PlainAuth("", smtpUserId, smtpPassword, host)

	body := strings.Join([]string{
		"From: " + fromAddress,
		"To: recipient@example.com",
		"Subject: Test Message",
		"MIME-Version: 1.0",
		"Content-Type: text/html; charset=UTF-8",
		"X-Helo-TrackLinks: true",
		"X-Helo-TrackOpens: true",
		"",
		"<html><body><h1>Test message HTML</h1><p>Test message paragraph</p></body></html>",
	}, "\r\n")

	if err := smtp.SendMail(addr, auth, fromAddress,
		[]string{"recipient@example.com"}, []byte(body)); err != nil {
		panic(err)
	}
}

Getting started

Core concepts

Platforms

Set up your sending domain

Create your first Channel

Create your SMTP user

Use your SMTP user credentials to send your first email

Need help sending your first email?

Contact us

Next steps

Sending transactional

Sending broadcasts

Domains

Channels

Activity

Suppressions

Webhooks

Set up your sending domain

Create your first Channel

Create your SMTP user

Use your SMTP user credentials to send your first email

​Need help sending your first email?

Contact us

​Next steps

Sending transactional

Sending broadcasts

Domains

Channels

Activity

Suppressions

Webhooks

Need help sending your first email?

Next steps