2022-10-01: released build 5.5r2
- added support for submission of compressed request payload with Transmissions API. Also,
introduced "<transmissions-api>.max-message-size" directive to specify the maximum size
allowed for the request payload (defaults to 100MB);
- updated User's Guide with instructions for setting up PowerMTA within Docker containers. This
feature is experimental;
- extended "virtual-mta-pool" syntax to support percentage-based routing for virtual MTAs.
This simplifies the configuration and offers more flexibility for balancing the load between
the various virtual MTAs within the virtual MTA pool;
- extended "<domain>.reroute-to-virtual-mta" directive syntax to take an optional parameter to
specify the time interval after which the reroute becomes effective. This could be useful to
automatically reroute recipients that stay in a queue for a long time to another virtual MTA
to have a better chance of getting delivered;
- introduced "<source>.require-starttls" directive to enforce encryption with STARTTLS for
inbound connections to improve security;
- fixed crash while processing a very deeply nested HTML when "<signals>.engagement-tracking"
is set to "sparkpost";
- other small improvements and fixes;
2022-06-03: released build 5.5r1
- added support for automatic inline seeding to help monitor the health of your email
sending campaigns;
- added ability to view additional deliverability metrics when using Signals. If you
currently use Signals, make sure the API key has "Account: Read" permissions before
upgrading to PowerMTA 5.5;
- improved Transmissions API to allow variable substitution and submission of email content
in "inline format". This allows you to submit the contents of your email in JSON which
includes the subject, headers, and the text/HTML contents for the body of your email.
PowerMTA will then compose a well-formed MIME-formatted email message for delivery;
- added support for metrics-based monitoring of PowerMTA with Prometheus;
- introduced a new REST API to manage configuration for "suppression-list"(s);
- added support for TLS certificate chain based authentication of SMTP users;
- added support for LDAP-based authentication of SMTP users via HashiCorp Vault;
- introduced "...-tls-min-version" and "...-tls-max-version" directives to control what
TLS protocol versions are allowed. This should be preferred over the existing
"...-tls-allow-..." directives which are now considered deprecated;
- introduced "...-tls-cipher-server-preference" directives to control whether to use
server’s preferences when choosing a cipher during a TLS connection;
- introduced a new "<include-config>" tag to support fetching configuration from external
sources through HTTP or HTTPS with customized HTTP headers;
- added "log-hires-timestamp" to configure millisecond precision for messages in log files;
- added a new "greylist" action to "smtp-pattern-list" to prioritize delivery of greylisted
recipients whenever the queue exits retry mode;
- added a new "defer-job" action to "smtp-pattern-list" to delay delivery of all recipients
belonging to a job within a queue;
- made hostname in "<proxy>.client" directive optional and use the virtual MTA's "host-name"
as the default;
- improved overall performance and reduced memory usage for Linux builds;
- upgraded to OpenSSL 1.1.1n, to get the latest bug fixes;
- other small improvements and fixes;
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;