Using Third-Party SMTP with Your Web App on IP ServerOne

Can my web app communicate with an external SMTP server?

✅ Yes, your web app hosted on IP ServerOne can communicate with third-party SMTP servers, including platforms like ZeptoMail, Gmail SMTP, SendGrid, Mailgun, and others. Our hosting environments—whether you’re on a VPS, Dedicated Server, or NovaCloud—support outbound SMTP traffic, allowing your application to send transactional or marketing emails via external email services.

🔧 General Requirements to Use External SMTP

1. Ensure SMTP Ports Are Open
   Most third-party SMTP providers use:
   • Port 587 (TLS)
   • Port 465 (SSL)
   • Port 25 (standard SMTP, sometimes restricted)

   🔍 Check your server’s firewall or hosting security settings to ensure these ports are not blocked.

2. Configure SMTP in Your Application
   Use your chosen provider’s recommended SMTP settings. Typically, this includes:
   • SMTP host (e.g., smtp.provider.com)
   • Port number
   • Authenticated email address (username)
   • App-specific password or token
   • TLS or SSL encryption
3. Run Connectivity Tests
   Use tools like telnet or openssl to test if the server can reach the SMTP host:

   telnet smtp.provider.com 587

   or

   openssl s_client -connect smtp.provider.com:465

4. Optional: Whitelist SMTP IPs
   If you’re using outbound filtering or have a restrictive firewall, make sure to whitelist the IPs or domain names of the SMTP provider you’re using.

Need Help?

If you’re unsure which SMTP settings to use or are facing connectivity issues, we’re happy to help.

• Email: support@ipserverone.com
• Phone: +603 2026 1688