The DNSSEC validator that guards DANE and the SPF, DKIM and DMARC lookups treated a DS query answered with nothing as an unsigned delegation. That is exactly what an attacker stripping the DS in transit shows a resolver: a signed zone quietly became unsigned, and DANE and validated TXT went with it. Anyone relying on DANE or on DNSSEC-validated SPF, DKIM or DMARC was affected. Before you upgrade Schema 6030 to 6031: one column on hm_fetchaccounts, added by the installer's database upgrade on every backend. From 6.2.25 or 6.2.26, run the installer. From earlier, read the 6.2.25 and 6.2.24 notes first. Security A missing DS is now proved missing (RFC 4035 §5.2, RFC 5155 §8). The resolver keeps the authority section of a negative answer and requires the parent's proof there: an NSEC at the delegation name with NS set and DS clear, an NSEC3 whose hashed owner matches with the same bits, or an Opt-Out NSEC3 covering the hash, each signed by the parent's key. A proof that fails to verify, has expired, claims a DS exists, or belongs to another name is no proof, and a delegation without one under a signed parent is now Bogus and blocked rather than Insecure. An unsigned parent, or a resolver that cannot be reached, still yields Insecure. The chain result is exposed as Diagnostics.DnssecChainStatus. Mail flow FetchAccount.MirrorFolders (schema 6031; "Mirror every folder" on an IMAP external account in the Control Panel) collects each remote mailbox into the local folder of the same name: every message byte for byte, with its \Seen \Flagged \Answered \Draft \Deleted flags, its internal date, and the remote hierarchy delimiter mapped to the local one. Nothing is delivered, so no rule, anti-spam or anti-virus touches a copy. Each folder records what it has collected, so a second poll takes only what is new. Days to keep messages 0 makes it a move. The Import Tool reads a Maildir: the INBOX and every Maildir++ folder beside it, with the flags the file names carry (;2, and !2, as well as :2,) and line endings made CRLF. An import into a folder a client has open now refreshes it, as a delivery does. Migration.md documents each route in and what it keeps: IMAP, mbox, Maildir, Outlook through IMAP (PST is deliberately not parsed), and bulk accounts. Full release notes, checksums and signatures

pre4 was withdrawn. Its installer could not create its own database: two SQL statements were written on consecutive lines, the script parser splits commands on a blank line, and SQL Server Compact, which a default install uses, rejected the pair as one command. The install succeeded, the service started, and it listened on nothing. Anyone who ran a fresh pre4 install was affected. The v6.2.22-pre4 tag still exists but has no release. Do not build from it. Before you upgrade This is pre-alpha. Nobody has run it on a production server, and the installer is smoke-tested on a throwaway CI runner only. Use a spare box. Upgrading from pre3 requires DBUpdater: the schema moves from 6019 to 6022 in three steps. DMARC, brought up to DMARCbis The DNS tree walk (RFC 9989 §4.10) replaces the Public Suffix List for deciding organizational domain. Bounded at eight queries per domain, cached five minutes. DmarcTreeWalkEnabled=0 keeps the list, which is also used whenever a lookup fails transiently. The np= tag (RFC 9989 §5.5.4) is honoured, so the resolver now reports the RCODE to tell NXDOMAIN from NODATA. Aggregate reports now emit the DKIM <selector> and SPF <scope> from RFC 7489, never sent before. Algorithms DKIM rsa-sha1 is refused (RFC 8301), on signing and verification. A domain configured to sign with it is signed rsa-sha256 instead and told so. DkimAcceptSha1=1 restores both halves. DKIM keys below 1024 bits are refused (RFC 8301 §3.2). SPF void lookups are capped at two (RFC 7208 §4.6.4). SpfVoidLookupLimit to change or disable. Certificates and delivery ACME renewal begins two thirds through the certificate's lifetime with a one-day floor, instead of a fixed 30 days. ARI (RFC 9773) is consulted hourly and the CA's window wins when offered, clamped to a day before expiry. A full mailbox is refused at RCPT with 452 4.2.2, ending the backscatter to forged envelope senders. RejectFullMailboxAtRcpt=0 restores the old behaviour. QuotaWarningPercent (default 90, 0 disables) sends one notice per crossing. Schema 6022. Operations Per-domain outbound relay, discussion #31. Order is route, then the sending domain's relay, then the server-wide relayer. Schema 6021. Queryable message trace, off by default. Schema 6020. ArchiveRetentionDays prunes ArchiveDir, 0 by default, .eml files only. The DMARCbis aggregate-report namespace (RFC 9990) is not implemented. Reports remain the RFC 7489 form. Full release notes, checksums and signatures

If you have a custom DNS server configured, every DNS lookup hMailServer made has been failing since 6.2.16. This release fixes it. Installations with no custom DNS server were never affected, because the server list is only built when one is set. 6.2.16 moved name resolution onto the asynchronous DnsQueryEx and gave the custom-DNS-server entry a destination port of 53. A DNS_ADDR carries a full SOCKADDR, so setting the port looks correct. It is not: the DNS client supplies the port itself, and with port 53 every query returns status 87 and no records. MX lookups for outbound delivery, DNSBL, SPF and SURBL all failed. It surfaced loudest as HM5507 The IP address for SpamAssassin could not be resolved, which is how #25 came in. A regression test now points DNSServer at TEST-NET-1 (192.0.2.1) and requires the lookup to time out; a timeout proves a packet left the machine. Before you upgrade The database schema moves from 6005 to 6011. DBUpdater applies it. Take a backup first. Settings are preserved. The [Settings] INI values move into the database for remote administration; the file still wins where both carry a value. Also in this release Active Directory can now create accounts, not just link them. Settings.PreviewDirectorySync and Settings.ApplyDirectorySync read an LDAP directory and create or update the mailboxes it says should exist, with a Control Panel page and an optional unattended schedule. A domain takes part only if its Active Directory domain name is set, so provisioning is opt-in per domain. Nothing is ever deleted. Sieve imap4flags now reaches the message. setflag, addflag, removeflag and the :flags tag were parsed and evaluated, then discarded at delivery. They are now applied to the stored message, and imap4flags has moved into the ManageSieve capability line. Only the five system flags can be stored; a keyword is logged rather than dropped in silence. GetUniqueMessageID could hand out the same UID twice, which makes a client show one message in place of another. An account address containing a colon accepted mail at RCPT TO, then failed when the message was filed: the local part becomes a directory name in the message store. Known issue: #26, partial FETCH BODY[]<offset.length> against 6.2.18, does not reproduce here against new tests that reassemble whole messages from chunks over FETCH and UID FETCH. If you can still reproduce it, post an IMAP protocol log. Full release notes, checksums and signatures

6.2.7 was a Control Panel usability release. The server core was unchanged since 6.2.6, so nothing in message handling moved. Every change sat in the .NET 8 administration Control Panel, closing the gaps that still forced hand-typed paths, external tools or guesswork. What it changed: File and folder pickers everywhere. Every field holding a file-system path gained a browse button: the backup destination and restore file, the archive folder, the ACME certificate folder, the OAuth2 public key, the REST API / Web Services TLS certificate and key files, the ClamWin executable and database folder, and the DKIM private key. One-click DKIM. Domain > DKIM gained Generate key pair. It creates an RSA-2048 key, saves the private key, fills in the path, and shows the exact selector._domainkey DNS TXT record (v=DKIM1; k=rsa; p=…) with a Copy button. No more running OpenSSL by hand. Passwords. All password boxes got a reveal toggle. The account editor and the quick-create form got a Generate strong password button, using a cryptographic RNG and copying to the clipboard. The external POP3 fetch-account password is masked rather than shown in clear text. Inputs. The auto-reply expiry became a date picker. Numeric server settings and the collection editors use up/down number boxes. Every editor dialog obeys Enter to save and Esc to cancel. MX query and Diagnostics output got a Copy button. Window state. The main window remembers its size, position and maximized state between sessions, and a save-confirmation toast appears after saving. Because the core was untouched, the regression suite result carried over from 6.2.6: 898 of 898 tests passing, zero failures, zero inconclusive, including live SpamAssassin, ClamAV with real EICAR detection, DMARC evaluation against live DNS, and TLS 1.2/1.3 handshakes end to end. One package shipped, hMailServer-6.2.7-x64.exe, 64-bit Windows only. Full release notes, checksums and signatures

6.0.0 is the first modernised release of the fork: 64-bit only, built with the VS2026 toolchain, with OpenSSL 4 and TLS 1.2 and 1.3 underneath. Build 4 is the production build, and it fixes the installer defect that made build 3 unusable on fresh installations. What the upgrade involved 6.0 was 64-bit only. The installer dropped the obsolete 2015-era UCRT, which had been included in Windows since Server 2016 / Windows 10. Upgrade notes and the full feature list are in the README. The installer fix Build 3 bundled VS2019-era VC++ runtime DLLs. The service loaded those instead of the current ones and crashed at startup with an access violation in msvcp140.dll on fresh installations. Build 4 ships the matching v145 (14.51) runtimes. Build 3 also fixed MySQL/MariaDB database creation, which was a script line-ending problem, and bundles libmysql.dll. What 6.0 brought OpenSSL 4, TLS 1.2 and 1.3 MTA-STS and DANE, with in-process DNSSEC validation ARC sealing and Ed25519 DKIM ACME (Let's Encrypt) built in REST admin API and Prometheus metrics IMAP MOVE, ID and SPECIAL-USE PBKDF2 password hashing The release was validated by the full regression suite: 898 of 898 tests passing, zero failures, run against a MariaDB (MySQL backend) instance, including live SpamAssassin, ClamAV with real EICAR detection, DMARC against live DNS, and TLS 1.2 and 1.3 end to end. Full release notes, checksums and signatures