📭 VPS Email Not Working — How to Restore Outgoing Mail

If your VPS is not sending or receiving emails, it's important to check SMTP server settings, DNS records, and port availability. This article provides a step-by-step guide to diagnosing and fixing email issues on your server.

📤 Check SMTP and Mail Ports

• 🔌 Ensure your SMTP server is running and listening on ports 25, 465, and 587
• 🧱 Check firewall or panel settings to make sure these ports are open
• 🌍 Verify your IP is not blacklisted by major email providers (use MXToolbox)
• 🧪 Test sending with telnet mail.domain.com 25 or swaks

🔧 Check Your Domain’s DNS Records

• 📌 The MX record defines where incoming emails are delivered
• 🛡 The SPF record lists IPs allowed to send mail for your domain
• 🔏 DKIM and DMARC improve trust and prevent spam
• 🧰 Use mxtoolbox.com or mail-tester.com to check

🧩 Other Possible Reasons for Email Failure

• ⚠ Mail service is not running (postfix, exim, sendmail)
• 📈 Server is overloaded or temporarily blocked
• 🔐 Antivirus or firewall is blocking mail traffic
• 🗃 Incorrect hostname or missing PTR (reverse DNS) record