hMailServer 6.2.6

A Control Panel and installer polish release, with one new opt-in server protocol mode. Download hMailServer-6.2.6-x64.exe below.
Highlights

    IMAP4rev2 (RFC 9051) as an opt-in session mode. The server advertises IMAP4rev2; ENABLE IMAP4rev2 switches the connection to RFC 9051 semantics (ESEARCH by default, \Recent/RECENT dropped from SELECT/EXAMINE/STATUS, the obsolete [UNSEEN] response code suppressed, UTF-8 acceptance). IMAP4rev1 behaviour is unchanged until a client opts in.
    Control Panel visual redesign. A central, theme-aware colour-token system replaces scattered hardcoded colours (success/warning/danger/info and the log palette now adapt to light/dark/high-contrast); a proper Fluent nav selection style plus a brand keyboard-focus ring; legible live-log colours on light theme; readable data grids and balanced columns; settings forms capped to a readable column with right-sized inputs; state-encoding KPI colours; softened destructive buttons; "no activity" chart placeholders; and a Welcome page of clickable quick-action tiles.
    Complete settings coverage. Every configurable server setting now has a GUI control: OAuth2 / external-token auth, SRS & BATV, submission/outbound rate limits, OpenTelemetry + slow-query log, connection timeouts, delivery/queue tuning, search indexing, message archiving and other INI knobs, Logging.Device/LogFormat, cache size caps, the domain Active Directory link, and a write-only secret editor. See settings.md.
    Two-factor authentication setup now renders a real scannable QR code (plus a grouped manual key with a copy button) and a larger, clearer verification field.
    Installer. DPI-scaled custom database-type page, removal of the dead legacy dependency installers (MSI/IE6/MDAC/JET/.NET 2.0), modernised copy, and refreshed brand imagery.

Validation

Server core validated by the full regression suite: 898 of 898 tests passing, including live SpamAssassin, ClamAV (EICAR), DMARC against live DNS, and TLS 1.2/1.3 handshakes end to end.
Assets

    hMailServer-6.2.6-x64.exe - the installer
    hmailserver.spdx.json - SPDX SBOM
    hmailserver.cyclonedx.json - CycloneDX SBOM