Home / Industry

Port25 Announces Release of PowerMTA V4.5r5

Port25, A Message Systems Company, has just released its latest version of PowerMTA v4.5r5 and PowerMTA Management Console v1.5r5. Highlighted below are the major features of this particular release.

SMTPUTF8 Support

Support for SMTPUTF8 is a specification whether one can submit internationalized email addresses per RFC6531, RFC6532, and RFC6533 to PowerMTA from the connecting IP address. When enabled or set to yes (or true), PowerMTA will list “SMTPUTF8” in the list of extended SMTP commands supported for the connecting IP, allowing the submitter to use internationalized email addresses in the SMTP envelope. Note that if the remote gateway for the domain does “not” advertize support for SMTPUTF8, PowerMTA will subsequently bounce the message(s) for the recipient out of the queue. If desired, SMTPUTF8 support can be disabled with the new per-<source> allow-smtputf8 directive.

UTF-8 is the dominant character encoding specification for the internet accounting for 87.1% of all Web pages as of June 2016. The Internet Mail Consortium (IMC) recommends that all email programs be able to display and create mail using UTF-8.

MX RollUp

MX Rollup List Allows one to define “rollup” queues based on the MX records of the recipient domain, in order to consolidate separate but related recipient domains into one queue. Messages moved into the roll up queue are handled as if they were one recipient domain with regards to rate limiting, connection caps, and other directives.

For example, since ‘msn.com’, ‘live.com’ and ‘outlook.com’ are all handled by the same exact MXs or Gateway, it makes sense to roll these up into a single queue (outlook.rollup for example) vs. being handled separately by PowerMTA. This feature works very well for the large mailbox providers that provide corporate hosting, for filtering/antispam cloud providers, or for large hosting providers in general that manage corporate email for tens or hundreds of thousands of various domains. To configure this feature, you need to define the MX record that maps to each rollup queue name along with the name of the rollup queue, which must end in “.rollup.” More than one MX can be mapped to the same rollup queue.

Additional Features include but not limited to:

  • Added support for internationalized domains to “pmta resolve”
  • Increased spool-max-recipients limit to ~16.8M and total-max-smtp-out to 10,000
  • Added ability to show per-recipient schedule in “pmta list”
  • Added support for pattern list header matching on Encoded-Words that include a language declaration, as specified by RFC2231

By Port25, A Message Systems Company

Port25, A Message Systems Company, provides highly focused email delivery software that addresses the ever-expanding needs of client communications and digital messaging apps. Port25’s flagship product, PowerMTA™, has a global footprint, with over 4,000 installations in more than 51 countries.

Visit Page

Filed Under


Commenting is not available in this channel entry.
CircleID Newsletter The Weekly Wrap

More and more professionals are choosing to publish critical posts on CircleID from all corners of the Internet industry. If you find it hard to keep up daily, consider subscribing to our weekly digest. We will provide you a convenient summary report once a week sent directly to your inbox. It's a quick and easy read.

I make a point of reading CircleID. There is no getting around the utility of knowing what thoughtful people are thinking and saying about our industry.

Co-designer of the TCP/IP Protocols & the Architecture of the Internet



Domain Names

Sponsored byVerisign

Threat Intelligence

Sponsored byWhoisXML API

IPv4 Markets

Sponsored byIPv4.Global

New TLDs

Sponsored byRadix


Sponsored byDNIB.com

Brand Protection

Sponsored byCSC


Sponsored byVerisign