Postfix 3.10.5, 3.9.6, 3.8.12, and 3.7.17 released
The latest stable release of Postfix, a widely used mail server, is now available. This new version, Postfix 3.10.5, has been released alongside legacy releases for older versions: 3.9.6, 3.8.12, and 3.7.17.
As an alternative to the popular Sendmail program, Postfix was initially developed at IBM Research with a focus on being fast, easy to administer, and secure. While it may look similar to Sendmail from the outside, its internal architecture is quite different.
Postfix 3.10 includes several important fixes that resolve compatibility issues between the Postfix SMTP client and MTA-STS policy plugins. Specifically, the corrected behavior now connects to an MX host only if its name matches any STS policy MX host pattern and matches the server certificate against the MX hostname. This new feature must be enabled in two places: by setting a new parameter called "smtp_tls_enforce_sts_mx_patterns" (defaulting to "yes") in Postfix and by enabling TLSRPT support in an MTA-STS plugin.
Additionally, the Postfix 3.10 release includes a workaround for when a TLSRPT policy-type value is "no-policy-found." In this case, the plugin will pretend that the TLSRPT policy domain value is equal to the recipient domain, ignoring the fact that different policy types (TLSA and STS) use different policy domains.
Other bug fixes included in the Postfix 3.10 release address a defect introduced in version 3.0, where the connection reuse logic of the Postfix SMTP client did not distinguish between sessions requiring SMTPUTF8 support and those that do not. This has been resolved by storing sessions with different SMTPUTF8 requirements under distinct connection cache storage keys and by not caching connections when SMTPUTF8 is required but the server does not support it.
The release also fixes a bug where the smtpd "disconnect" command statistics did not count commands with "bad syntax" and "bad UTF-8 syntax" errors. Furthermore, Postfix 3.10 includes a fix for DBM library support on Solaris, which was inadvertently broken in an earlier patch.
Finally, the release allows for preliminary 'size' records in maildrop queue files created with Postfix 3.11 or later, thereby avoiding potential warnings when rolling back to an older version.
Legacy releases of Postfix are also available, including versions 3.9.6, 3.8.12, and 3.7.17, which include fixes for various bugs such as non-deterministic build outputs and missing meta_directory settings in the stock main.cf file.
The updated source code for Postfix can be found at the mirrors listed on the official website.
