Skip to main content
Send transactional emails via SMTP instead of the REST API. This is useful for applications that already have SMTP integration (Laravel, WordPress, legacy systems) or prefer the standard email protocol.

​
SMTP Credentials

Use these credentials to configure your application:
SettingValue
Hostsmtp.sequenzy.com
Usernameapi
PasswordYour API key
The username can be anything—only the password (your API key) is used for authentication. We recommend api for clarity.

​
Port Options

Sequenzy supports multiple ports for different network environments:
PortSecurityDescription
587STARTTLSRecommended. Starts unencrypted, upgrades to TLS.
465Implicit TLSEncrypted from connection start (legacy SMTPS).
2525STARTTLSFallback port for firewalled networks (ISPs blocking 587).

​
Which port should I use?

  • Port 587 is the standard for email submission and works with most applications
  • Port 465 is for legacy applications that require implicit TLS (connect with SSL from the start)
  • Port 2525 is useful if your ISP or firewall blocks standard SMTP ports

​
Prerequisites

Before sending via SMTP:
  1. Create an API key in Settings → API Keys
  2. Verify your domain in Settings → Domains
  3. Configure a sender profile with the email address you’ll send from

​
Quick Start

import nodemailer from "nodemailer";

const transporter = nodemailer.createTransport({
  host: "smtp.sequenzy.com",
  port: 587,
  secure: false, // true for port 465, false for 587/2525
  auth: {
    user: "api",
    pass: process.env.SEQUENZY_API_KEY,
  },
});

await transporter.sendMail({
  from: "you@your-verified-domain.com",
  to: "recipient@example.com",
  subject: "Hello from Sequenzy",
  html: "<h1>Hello!</h1><p>This email was sent via SMTP.</p>",
});

​
Framework Integrations

​
Laravel

Update your .env file: 
MAIL_MAILER=smtp
MAIL_HOST=smtp.sequenzy.com
MAIL_PORT=587
MAIL_USERNAME=api
MAIL_PASSWORD=ek_your_api_key
MAIL_ENCRYPTION=tls
MAIL_FROM_ADDRESS=you@your-verified-domain.com
MAIL_FROM_NAME="Your App"
Then send emails using Laravel’s Mail facade: 
Mail::to('recipient@example.com')->send(new WelcomeEmail());

​
Django

Update your settings.py: 
EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST = 'smtp.sequenzy.com'
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = 'api'
EMAIL_HOST_PASSWORD = os.environ.get('SEQUENZY_API_KEY')
DEFAULT_FROM_EMAIL = 'you@your-verified-domain.com'
Then send emails: 
from django.core.mail import send_mail

send_mail(
    'Hello from Sequenzy',
    'Plain text body',
    'you@your-verified-domain.com',
    ['recipient@example.com'],
    html_message='<h1>Hello!</h1><p>This email was sent via SMTP.</p>'
)

​
Ruby on Rails

Update config/environments/production.rb: 
config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  address: 'smtp.sequenzy.com',
  port: 587,
  user_name: 'api',
  password: ENV['SEQUENZY_API_KEY'],
  authentication: :plain,
  enable_starttls_auto: true
}

​
WordPress

Install a plugin like WP Mail SMTP and configure:
  • SMTP Host: smtp.sequenzy.com
  • Encryption: TLS
  • SMTP Port: 587
  • SMTP Username: api
  • SMTP Password: Your API key

​
Features

​
Same Pipeline as REST API

SMTP emails go through the same processing pipeline:
  • Analytics: All emails appear in your Sent Emails dashboard
  • Tracking: Opens and clicks are tracked (if enabled)
  • Branding: Footer added for free tier accounts
  • Rate limits: Same limits apply as REST API

​
Security Enforcement

The SMTP server applies the same security checks:
CheckDescription
API key validationPassword must be a valid API key
Domain verificationSender domain must be verified
Bounce protectionEmails to known bounced addresses are rejected
Rate limiting100 emails/minute per company
Account statusPaused/suspended accounts cannot send

​
Message Limits

LimitValue
Max message size25 MB
Max To recipients50
Max CC recipients50
Max BCC recipients50

​
Rate Limits

LimitValue
Emails per minute100 (per company)
Auth failures before lockout5 (per IP)
Lockout duration15 minutes

​
Troubleshooting

Your ISP or firewall may be blocking SMTP ports. Try port 2525 instead of 587.
  • Ensure you’re using a valid API key as the password
  • The API key should start with ek_
  • Check that the key hasn’t been revoked in your dashboard
The sender domain (the domain in your From address) must be verified in Settings → Domains before you can send.
The recipient email may be on the bounce list. Check your Sent Emails dashboard for previous bounces to this address.
You’ve exceeded 100 emails/minute. Wait a minute and try again, or contact support to increase your limit.

​
FAQ

Yes, the username is ignored—only the password (your API key) is used for authentication. We recommend using api for clarity.
Yes, all emails sent via SMTP appear in your Sent Emails dashboard with full analytics, same as REST API emails.
Yes, if tracking is enabled for your account. SMTP emails use the same tracking pixel and link rewriting as REST API emails.
Yes, standard MIME attachments work. Maximum total message size is 25MB.
  • Port 587 (STARTTLS): Starts unencrypted, then upgrades to TLS. This is the modern standard.
  • Port 465 (Implicit TLS): Encrypted from the start. This is a legacy method but still supported.
Use port 587 unless your application specifically requires implicit TLS.
Some ISPs and corporate firewalls block standard SMTP ports (25, 587, 465). Port 2525 is an alternative that’s less likely to be blocked.
SMTP is designed for transactional emails. For bulk marketing campaigns, use the Campaign feature in the dashboard or REST API.