Postfix 3.11.0 is phasing out support for BerkeleyDB, a feature still used by many mail administrators for hash and btree lookup tables, and provides guidance on migrating to LMDB or CDB to minimize downtime. The update also includes changes to TLS settings that enhance security for SMTP and LMTP connections while introducing stricter requirements for encrypted transport, which may lead to delivery issues if not properly configured. Additionally, the release introduces new features like support for the REQUIRETLS verb and JSON output options, which may benefit developers but might be excessive for average administrators. Other practical changes include improved error handling for milters, which helps manage resource consumption on mail systems dealing with high volumes of spam

Postfix 3.11.0: How to Migrate BerkeleyDB Tables Before They Vanish

Postfix 3.11.0 drops BerkeleyDB support, a legacy feature still relied on by many mail administrators for hash: and btree: lookup tables. The update explains how to migrate to LMDB or CDB before the support disappears, reducing downtime during future upgrades. It also highlights TLS changes that tighten security for SMTP and LMTP connections while noting practical workarounds for compatibility with MTA‑STS policies.

Postfix 3.11.0: How to Migrate BerkeleyDB Tables Before They Vanish @ Linux Compatible