3CX SMTP, RPS and global IP Blacklist security and reliability changes.

3CX Version 18 is End of Life (EOL). Therefore, several security and service-reliability guarantees, including 3CX SMTP, Remote Provisioning Service (RPS) and the Automatic Global IP Blacklist, will no longer receive updates or maintenance.

Customers remaining on V18 should take note of the following upcoming changes.

3CX SMTP Service

The built-in 3CX SMTP service for Version 18 will be discontinued. From 1st May, 2026, emails sent by 3CX cloud infrastructure for V18 systems will be blocked. To continue sending emails you must configure your own SMTP service (Gmail, Microsoft 365 etc).

Remote Provisioning Service (RPS)

The 3CX RPS service is used when provisioning IP phones using the 3CX RPS provisioning method. This allows admins to auto-provision supported IP phones without entering the provisioning URL or config file. Instead, the phone can simply be rebooted and the user enters their extension number and PIN, allowing the device to connect and configure automatically. This method saves a lot of admin time.

It should be noted that security updates for the Remote Provisioning Service (RPS) will no longer be provided for Version 18. While existing functionality may continue to operate, no further security patches will be applied.

Automatic Global IP Blacklist

The Global IP Blacklist is a central database of IP addresses blacklisted by one or more 3CX systems. Each instance participating in the 3CX global anti-hacking defense program contributes to a worldwide community of IP-PBX servers, helping protect systems by sharing known malicious IP addresses. You can learn more about how this works here.

The Automatic Global IP Blacklist will also no longer receive security updates for Version 18. So whilst Version 18 systems will still retain this functionality, no further security updates will be provided. In summary this means:

  • No new malicious IP intelligence updates
  • No ongoing threat feed updates
  • No security improvements to blacklist mechanisms

Without active blacklist updates, systems may become more vulnerable to emerging threats.

What This Means for V18 Users

While some components may continue functioning temporarily, if you’re still running Version 18, your system will no longer receive:

  • Security updates
  • Threat intelligence updates
  • Service reliability guarantees

Running Version 18 in production environments is no longer recommended!

Why You Should Plan Your Move to V20

  • Active security maintenance
  • Ongoing blacklist updates
  • Supported SMTP services
  • Technical support
  • Continuous feature development

Upgrading is easy and ensures your system remains secure, supported and compliant with current platform standards.

We strongly encourage all customers to prioritize their transition to Version 20 to avoid service interruptions and security exposure.

Quick Audio Recap

For those who prefer listening instead of reading, we’ve prepared a short audio recap summarizing the key points of this update.