Both came from an adversarial audit that found and fixed 21 defects. No database change: schema version 6005, unchanged. The regression suite passed 1026 of 1026.

Mail loss and stability

• Every string SQL parameter on MS SQL and SQL CE was bound from freed memory.
• A failed transaction start leaked its pooled connection, and after a few occurrences SMTP, IMAP and POP3 blocked until a service restart.
• A failed IMAP folder insert was reported as success, so messages filed into it were written to disk with nothing to find them by.

Security

• DKIM test mode (t=y) turned a failed signature into a pass, which then satisfied DMARC alignment. A failure in test mode is now neutral, per RFC 6376.
• IMAP SASL credentials were logged verbatim: AUTHENTICATE PLAIN passwords and XOAUTH2/OAUTHBEARER tokens.
• Only the first DKIM key record at a selector was read, so roughly half of a rotating sender's mail failed verification.
• MTA-STS enforcement and MX failover were lost for recipients past the first batch.

Protocol and Control Panel

• SELECT/EXAMINE report a sequence number in [UNSEEN], as RFC 3501 requires, not a UID.
• Reverse-DNS lookups for the Received header moved to their own thread pool, completing the 6.2.13 fix.
• Backup would not start (#19): a Control Panel call to a method the backup interface does not have.
• Ctrl+K now searches settings, all 227 indexed by label and INI key. Logging, scanner timeout, indexing and retry settings moved to the pages that own them, which is where #16 went.

Full release notes, checksums and signatures