Powermta - 60r3

If you decide to modernize, consider:

This release represents a major overhaul of the underlying architecture compared to legacy versions (v4.x).

Unlike cloud senders, PMTA requires manual warmup. Use conditional throttling: powermta 60r3

<domain gmail.com>
  max-smtp-out 20           # Start low
  max-msg-rate 50           # Then increase by 10% daily
  warmup "2d"               # PMTA v6 feature: automatically ramp up over 2 days
</domain>

This feature allowed external scripts (Python, PHP, Node.js) to make real-time allow/deny decisions. For example, before accepting a message from a pickup directory, PowerMTA 60r3 could send an HTTP POST to http://localhost:8080/check with the recipient domain. If the script returned DENY, the message was rejected.

PowerMTA 60r3 prioritizes modern email authentication standards critical for compliance with new policies from Google and Yahoo (effective 2024). If you decide to modernize, consider:

PowerMTA 60r3 is a specialized enterprise-grade email delivery agent (MTA) developed by Port25 Solutions. It is designed to handle high-volume outbound and inbound email traffic with a focus on deliverability, throughput, and granular control. This release marks a significant evolution from the v4.5 series, introducing architectural modernization, enhanced security protocols, and improved performance scalability suitable for modern cloud-native environments.

Consider upgrading if you need:

A default installation of 60r3 will send email, but it won't send well. Below is a battle-tested configuration template for high deliverability.