High-Deliverability SMTP Relay for Any Application
Plug enterprise email delivery into WordPress, Laravel, Postfix, Nodemailer, or any existing system in minutes. Standard TLS ports 587 and 465 with 99.99% uptime.
apikey | Password: mf_live_YOUR_API_KEYConfigure your stack in seconds
Copy the snippet directly into your configuration file.
// Configure WordPress to send through Mailofly SMTP Relay
define( 'SMTP_HOST', 'smtp.mailofly.com' );
define( 'SMTP_PORT', 587 );
define( 'SMTP_SECURE', 'tls' );
define( 'SMTP_AUTH', true );
define( 'SMTP_USER', 'apikey' );
define( 'SMTP_PASS', 'mf_live_YOUR_API_KEY' );
define( 'SMTP_FROM', 'orders@yourdomain.com' );
define( 'SMTP_NAME', 'Your Store Name' );Why Developers Choose Mailofly SMTP
Skip server blocklists, port 25 bans, and complex Postfix configurations. We handle sender authentication and delivery.
Automated DKIM & SPF Signatures
Every email relayed through our SMTP cluster is cryptographically signed with your 2048-bit DKIM key and matched with your SPF records to guarantee inbox delivery.
Real-Time Handshake Logs
Diagnose deliverability issues instantly. Inspect complete SMTP handshake logs, including EHLO, STARTTLS negotiations, AUTH states, and recipient MX response codes.
Zero Throttle Queueing
Avoid connection timeout errors. Mailofly's SMTP ingest servers buffer burst traffic smoothly and deliver sequentially to strict ISPs like Gmail, Yahoo, and Outlook.
Enforced TLS 1.3 Encryption
Support for modern TLS cipher suites on both Port 587 (STARTTLS) and Port 465 (implicit TLS). Your email credentials and payloads remain encrypted in transit.
Global Low-Latency Ingest
Connecting from North America, Europe, or Asia-Pacific? Anycast edge routing ensures the nearest Mailofly SMTP server establishes socket handshakes in milliseconds.
Unified SMTP & API Dashboard
Emails sent via SMTP share the exact same deliverability radar, open/click analytics, suppression lists, and webhooks as emails sent through our REST API.
SMTP Relay vs. REST Email API
Choose the best delivery method for your stack—or use both simultaneously.
| Criteria | SMTP Relay | REST Email API |
|---|---|---|
| Best Use Case | WordPress, WooCommerce, CMS, Postfix, legacy software | Next.js, Node.js, serverless functions, mobile apps |
| Setup Complexity | Zero code: enter host, port, user, and password | Install SDK or make HTTP POST request |
| Latency & Overhead | Socket handshake required (~200–500ms) | Sub-100ms HTTP REST execution |
| Advanced Features | Custom headers, MIME bodies, standard attachments | Dynamic template variables, tags, webhook signatures |
| Log Tracking | Full 30-day dashboard inspect | Full 30-day dashboard inspect |
Frequently Asked Questions about our SMTP Relay
Get Your Free SMTP Credentials in 30 Seconds
Start with 3,000 free emails every month. Verify your domain and connect any app via port 587 or 465.