Local delivery could lose a message with no trace. When the account-level copy could not be written, LocalDelivery reported HM5209 and returned, but the recipient row was deleted anyway and the queued message with it. The sender had already been given 250 and the recipient never heard of it. Anyone running a message store near full was exposed. The sender is now told.

This is an alpha. Do not put it on a production mail server.

What the upgrade involved

The schema moves 6022 to 6025 in three registered steps, and it is one way. An older server refuses to run against a newer dbversion, so rollback needs a pre-upgrade database backup and a data-directory backup.

The 6024 to 6025 step widens hm_messages.messageflags from tinyint to smallint on MS SQL, SQL CE and MySQL/MariaDB. That is a table rewrite on your largest table, holding locks throughout. Size the maintenance window to your hm_messages row count. PostgreSQL is unaffected.

Silent upgrades with /VERYSILENT previously hung forever on a modal password dialog. Fixed.

Five COM properties added during the 6.2.22 pre-releases were declared mid-interface, shifting the vtable on AntiSpam, Account, Application and GlobalObjects. They are appended now, restoring binary compatibility with 6.2.21. Late-bound scripts were never affected. Recompile anything early-bound against a 6.2.22 pre-release.

Three new defaults change behaviour. MinimumFreeDiskSpaceMB=100 refuses new mail below the floor, 452 4.3.1 at MAIL FROM and NO [UNAVAILABLE] at IMAP APPEND. WindowsEventLogEnabled=1 forwards errors to the Windows Application log under the source hMailServer. DatabaseStatementTimeout=30 is untested on MySQL and PostgreSQL, the two backends it was built for.

Existing per-account out-of-office replies now apply RFC 3834 suppression and stop answering bounces, list traffic and anything carrying Auto-Submitted or List-* headers.

Also in this release

• PROXY protocol v1/v2 and XCLIENT in front of SMTP, so DNSBL, SPF, greylisting and auto-ban see the real client. Both ship off with empty trust lists.
• Shared and delegated IMAP mailboxes at #Users.owner@domain.folder, gated on RFC 4314 ACLs. On by default, enableimapacl ships as 1.
• RFC 3030 BINARYMIME. Relay of a binary message is refused 554 5.6.3 rather than converted.
• RFC 3464 bounces. Every NDR is now multipart/report. Re-check anything parsing whole bounce bodies.
• External HTTP filtering hook (FilterHookUrl, FilterHookTimeoutSeconds default 10), plain HTTP only.
• Sender blacklist, per-account spam thresholds, distribution-list moderation, domain-wide out-of-office, IPv6 on the REST and metrics listeners.

Full release notes, checksums and signatures