Mail::DMARC::Report::URI - a DMARC report URI


version 1.20230215


  use Mail::DMARC::URI;
  my $duri = Mail::DMARC::URI->new;
  my $uri_ref = $duri->parse(',');
  foreach my $u ( @$uri_ref ) {
      my $method = $u->{uri};
      my $max    = $u->{max_bytes};
      ... do some URI stuff ...


defines a generic syntax for identifying a resource. The DMARC mechanism uses this as the format by which a Domain Owner specifies the destination for the two report types that are supported.

The place such URIs are specified (see Section 6.2) allows a list of these to be provided. A report is to be sent to each listed URI. Mail Receivers MAY impose a limit on the number of URIs that receive reports, but MUST support at least two. The list of URIs is separated by commas (ASCII 0x2C).

Each URI can have associated with it a maximum report size that may be sent to it. This is accomplished by appending an exclamation point (ASCII 0x21), followed by a maximum size indication, before a separating comma or terminating semi-colon.

Thus, a DMARC URI is a URI within which any commas or exclamation points are percent-encoded per [URI], followed by an OPTIONAL exclamation point and a maximum size specification, and, if there are additional reporting URIs in the list, a comma and the next URI.

For example, the URI "!50m" would request a report be sent via email to "" so long as the report payload does not exceed 50 megabytes.

A formal definition is provided in Section 6.3.


  dmarc-uri = URI [ "!" 1*DIGIT [ "k" / "m" / "g" / "t" ] ]
            ; "URI" is imported from [URI]; commas (ASCII 0x2c)
            ; and exclamation points (ASCII 0x21) MUST be encoded

URI is imported from RFC 3986:

Only mailto, http, and https URIs are currently supported, examples:

With an optional size limit (see SIZE LIMIT).


A size limitation in a dmarc-uri, if provided, is interpreted as a count of units followed by an OPTIONAL unit size ("k" for kilobytes, "m" for megabytes, "g" for gigabytes, "t" for terabytes). Without a unit, the number is presumed to be a basic byte count. Note that the units are considered to be powers of two; a kilobyte is 2^10, a megabyte is 2^20, etc.


  • Matt Simerson <>

  • Davide Migliavacca <>

  • Marc Bradshaw <>


This software is copyright (c) 2023 by Matt Simerson.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.