Latest Release of PowerMTA v5.0 – Updates from v5.0r6 to v5.0r9

Hey there! We’d like to take a moment to talk about PowerMTA, often called PMTA. If you’ve spent any time working in email marketing or tech, chances are you’ve heard of it. In short, it’s a commercial Message Transfer Agent (MTA) that has built quite a reputation for dependable and efficient email delivery. Major Email Service Providers (ESPs) and large enterprises—including MailChimp, Microsoft, and IBM—rely on PMTA for their email operations, which speaks volumes about its reliability.

If you ever find yourself unsure about installing or configuring PowerMTA, don’t worry. We’re here to help! Feel free to reach out at ipwarmup.com/powermta, and we’ll guide you through the process step by step.

We’re especially excited about the recent release of PowerMTA v5.0r9, which was launched on November 18, 2021. This update builds on the features introduced since the earlier v5.0r6 release, improving stability, performance, and the overall user experience. The PowerMTA team never stops refining their software, and it’s great to see them continually raising the bar.

2021-11-18: released build 5.0r9

    - optimized the implementation of "max-memory-usage-percent" directive and changed it to
      be disabled by default;

    - disabled jobs from being listed by default on domain's detail page in web monitor
      as a performance optimization; use <domain>.track-jobs directive to enable it;

    - other small improvements and fixes;

2021-04-28: released build 5.0r8

    - extended domain-key directive to support using keys stored in HashiCorp Vault for
      DKIM signing;

    - added support for adding recipient metadata and tags from X-MSYS-API header to Signals
      ingest data;

    - introduced a new directive - smtp-proxy-source-host - to support the use of multiple,
      possibly independent, proxy servers from within a single virtual MTA;

    - added additional connection-related information to accounting files when delivering email
      through a proxy server;

    - optimized check for expired messages in a queue containing recipients with a delivery
      schedule;

    - upgraded to OpenSSL 1.1.1k, to get the latest bug fixes;

    - upgraded to PCRE 8.44, to get the latest bug fixes;

    - other small improvements and fixes;

2021-01-07: released build 5.0r7

    - added support to configure click tracking and top/bottom open pixel insertions independently
      from each other when using engagement tracking with SparkPost Signals;

    - extended "smtp-pattern-list" to allow specifying the time interval after which a queue will
      return to normal mode after being set into backoff mode with the mode=backoff action;

    - extended "include" directive to support fetching configuration from external sources
      through HTTP or HTTPS;

    - added support for DKIM signing DSN emails issued by PowerMTA;

    - added "pmta show vmta-settings" command to view settings of a particular VirtualMTA;

    - added support for customizing key length of DH (Diffie-Hellman) parameters used during a
      TLS 1.1 or TLS 1.2 handshake;

    - added "max-memory-usage-percent" directive to configure the maximum memory consumption
      of the PowerMTA process beyond which it will stop accepting incoming email;

    - fixed a bug in cold VirtualMTA selection which reduced the amount of email rerouted to
      a cold virtual MTA when MX rollup patterns are also configured;

    - upgraded to OpenSSL 1.1.1i, to get the latest bug fixes;

    - other small improvements and fixes;

2020-10-27: released build 5.0r6

    - added support for SMTP MTA Strict Transport Security (MTA-STS) mechanism, described
      in RFC 8461, for enforcing secure delivery of email over encrypted connections
      to remote domains that support it;

    - added support for persistent connections for inbound HTTP connections when using
      Transmissions API to submit messages to PowerMTA;

    - greatly improved speed of reload operation when configuration file has large number
      of domain keys and virtual MTAs defined;

    - disallowed TLSv1.1 by default for incoming SMTP and HTTP connections to PowerMTA since
      it is now considered deprecated;

    - added support for HAProxy protocol version 2 for outbound traffic from PowerMTA;

    - fixed bugs in webhooks delivery when using compressed delivery over HTTPS and reduced
      frequency of retries when webhook connection attempts fail;

    - added List-Unsubscribe-Post to the default list of headers that are included in
      DKIM signature;

    - upgraded to OpenSSL 1.1.1g, to get the latest bug fixes;

    - other small improvements and fixes;

For those who want to dig deeper and see how the platform has evolved, we recommend checking out the previous change logs here:
ipwarmup.com/blog/tag/powermta-change-log/

We hope this helps you stay informed about PowerMTA’s latest developments. If you have any questions or need further assistance, don’t hesitate to get in touch with us!