MailFerry v2.1.0 — IMAP Migration & Sync

MailFerry v2.1.0 — Feature Release

High-Performance Native IMAP Migration Engine.

OAuth 2.0 / modern authentication with a first-class mailferry auth
lifecycle, IMAP MULTIAPPEND batching, evidence-based server
identification, and a substantially polished operator experience.

Migration correctness, the statistics identity, terminal sanitisation
and SIGHUP handling are unchanged and still test-enforced. Existing
password migrations and existing mailferry.db / mailferry.toml
files continue to work untouched.

Added

• OAuth 2.0 / modern authentication (SASL XOAUTH2, and
  OAUTHBEARER for standards-compliant servers). First-class
  Microsoft 365 / Exchange Online and Google Workspace / Gmail,
  plus a generic provider. Source and destination authenticate
  independently — password↔OAuth, or two different providers, in one
  run. The canonical 10-column CSV is unchanged: an endpoint opts in
  with an oauth:<profile> password cell.
• Three authentication models, kept deliberately distinct:
  delegated (one user's own mailbox), application (Microsoft 365
  app-only, IMAP.AccessAsApp — one tenant app → many mailboxes) and
  service_account (Google domain-wide delegation → many mailboxes).
  An administrative profile mints its tenant token once and shares
  it across every mailbox and worker in the run.
• mailferry auth command family — add / list / show /
  test / refresh / remove. Browser loopback + PKCE (RFC 8252),
  headless device code (RFC 8628) for Microsoft, and manual redirect
  capture for Google. --user names the mailbox you mean: it is sent
  as the OIDC login_hint and the account that actually signed in is
  verified afterwards — on a mismatch nothing is saved.
  auth test is a staged diagnostic: token → TLS → SASL → LIST,
  then the server's full capability list and a plain-language verdict.
• Secrets are never stored in configuration. Client secrets,
  refresh tokens and service-account keys are held as external
  references (env: / file: / keychain: / dpapi: / cmd:) and
  resolved at run time — never written to mailferry.toml, the State
  Database, logs, reports or traces. Storage uses the OS-native secure
  store: macOS login keychain, Linux Secret Service, Windows DPAPI
  (current-user scope), with a documented 0600 fallback.
• IMAP MULTIAPPEND (RFC 3502) — several messages uploaded in one
  APPEND command when the destination advertises it. On by default
  with automatic batch sizing (--multiappend auto|off,
  --multiappend-batch-size auto|N). On the built-in benchmark, 400
  messages went from 400 append commands to 50. It is an
  optimisation and nothing more: bodies still stream (memory stays
  proportional to a chunk, not a batch), an unsupported destination
  transparently uses one append per message, and every message keeps
  its own durable state, destination UID, flags and INTERNALDATE.
  Batch size is not concurrency.
• Evidence-based server identification. MailFerry reports what the
  server positively says about itself — OAuth provider, RFC 2971 IMAP
  ID, vendor-private CAPABILITY, greeting banner, TLS certificate —
  and displays Unknown when the evidence is insufficient. There is
  no hostname table, provider list or fingerprint database, and the
  identifier is never given the hostname, so guessing from a domain is
  structurally impossible.
• Adaptive Dashboard. A Source / Destination panel reporting host,
  server, auth, negotiated TLS and that connection's current speed;
  for heterogeneous (MSP) runs it aggregates by identified platform
  rather than showing one mailbox as if it spoke for the run. Plus a
  live F3 mailbox inspector, one unified quit confirmation (Esc
  never exits), a Runtime that freezes on completion, and a single
  authoritative completion timestamp.
• Interactive F9 Settings and an expanded typed configuration
  surface, saved atomically to mailferry.toml with comments
  preserved.
• Documentation: docs/OAUTH.md (the authentication model),
  docs/OAUTH-SETUP.md (step-by-step Microsoft Entra and Google Cloud
  configuration, verified against the official provider documentation
  on 01/08/2026) and docs/MULTIAPPEND.md.

Fixed

• Cancelling a run no longer abandons appends already on the wire.
  A stopped transfer settles the commands it has already sent, so each
  message's outcome is recorded rather than left ambiguous — removing
  a path where a resume could copy a message twice.
• A starting migration could fail if something was watching it.
  SQLite does not apply busy_timeout to PRAGMA journal_mode, so a
  read-only observer (mailferry attach) opening the file during the
  initial WAL switch could abort the run with database is locked.
  Schema initialisation now retries on lock contention.
• keychain: secret references are now resolvable on Linux (Secret
  Service via secret-tool); previously a reference could be stored
  that only macOS could read back.

Verification

gofmt, go vet (darwin/linux/windows), the full unit and end-to-end
suites and the race detector all pass. Two clean builds of this commit
are byte-identical.

Known limitations

• macOS binaries are not yet Apple-notarised — Gatekeeper may block
  the first launch and a one-time Open Anyway is expected. See
  docs/INSTALLATION-MACOS.md;
  never disable Gatekeeper. The signing pipeline is documented in
  docs/RELEASING-MACOS.md and planned for a future release.
• Terminal/PTY regression tests are Linux-only and were not executed on
  the macOS build host.
• Real-provider verification to date covers the Microsoft 365
  delegated browser flow. The device-code, app-only, Google
  delegated and Google domain-wide-delegation paths, Windows DPAPI
  storage and Linux Secret Service are implemented and unit-tested
  against mocked providers, but have not yet been exercised against
  live tenants.

Verifying your download

shasum -a 256 -c SHA256SUMS      # macOS
sha256sum -c SHA256SUMS          # Linux

Full changelog:
https://github.com/ajsap/mailferry/blob/main/CHANGELOG.md

MailFerry v2.0.3 — IMAP Migration & Sync

MailFerry v2.0.3 — Patch Release

High-Performance Native IMAP Migration Engine.

The polished Results experience: an interactive migration now finishes
on a native Results screen inside the TUI — verdict, statistics,
per-mailbox outcomes and a concise "Needs attention" summary — instead
of dropping to a raw text dump. Quitting returns a clean shell with a
short confirmation, never a duplicate report.

Added

• Results TUI with distinct verdicts: MIGRATION COMPLETE ·
  COMPLETED WITH WARNINGS · NOTHING NEW TO COPY · DRY RUN. Run and
  Messages panels, problems-first mailbox table, contextual panels
  (adopted, prior-confirmed, dry-run plan, date range, portable mode),
  Enter/F-keys/S/Q navigation. F6 doubles as the Failed Messages
  browser after completion. Headless/non-TTY output remains structured
  text — never a forced TUI.
• Counter completeness: synced = copied + adopted + prior-confirmed + planned is now a tested invariant of the real
  engine; new contextual lines and results.csv columns (msgs_prior,
  msgs_planned) make idempotent reruns and dry runs self-explanatory.
• RFC 2047 subject decoding in every interactive failed-message
  surface, with clean ellipsis truncation and safe fallback.
• Restored v1.x summary details: Run ID, mailbox timings, retries,
  stalls, stale/remote/cancelled reporting, warned-mailbox breakdown.

Fixed

• Percentages never overstate completion: 100% appears only when
  every message is genuinely accounted for (26,081 of 26,089 renders
  99.9%, not 100%); progress also never rounds down to 0%.

No engine, protocol, state or data-handling changes. Existing
mailferry.db and mailferry.toml remain fully compatible. The v2.0.2
terminal sanitisation fix (confirmed on the affected macOS arm64
system) is preserved and re-verified in this release's gate.

macOS note: binaries remain unsigned/not notarised — Gatekeeper asks
for a one-time "Open Anyway" approval
(guide).

Verify downloads: shasum -a 256 -c SHA256SUMS
Issues: https://github.com/ajsap/mailferry/issues
Author: Andy Saputra andy@saputra.org · Licence: GNU AGPL v3.0

MailFerry v2.0.2 — IMAP Migration & Sync

Superseded release

This version contains known issues that have been resolved in v2.0.3. Users should upgrade to the latest stable release. This release is retained for historical and reproducibility purposes.

Upgrade: MailFerry v2.0.3 — latest stable release

---

MailFerry v2.0.2 — Patch Release

High-Performance Native IMAP Migration Engine.

Fixes the "stair-step" terminal output defect at its actual root cause
— reproduced on real macOS arm64 with v2.0.0/v2.0.1, and this fix
verified on that same real environment before release.

Fixed

• Stair-step output: MailFerry writes ordinary "\n" line output
  and relies on the terminal’s output post-processing (OPOST/ONLCR)
  for carriage returns. A terminal left in a raw-ish state by a
  previously crashed full-screen program renders every subsequent run
  as a stair-step from the very first banner line — and v2.0.1’s
  capture/restore preserved that inherited state instead of healing
  it. MailFerry now repairs the stty sane newline flag subset before
  its first byte of output (only when actually broken, with a one-line
  notice), and every capture thereafter snapshots the sane state — no
  exit path can hand a broken terminal back to the shell. Already-sane
  terminals are untouched; pipes/non-TTY output are never modified;
  TUI, headless and SSH/tmux/screen behaviour is unchanged.

Added

• mailferry term-diag — supported terminal self-test (no servers, no
  credentials, no data).
• MAILFERRY_TERM_DIAG=FILE — per-stage termios flag logging for field
  diagnosis (flags only — never mailbox data).
• PTY-level regression tests asserting that every rendered line begins
  at column 1 on clean and pre-broken terminals, and that a broken
  terminal ends healed.

No engine, protocol, state or data-handling changes: migration
behaviour is identical to v2.0.0/v2.0.1. Existing mailferry.db and
mailferry.toml are fully compatible.

macOS note: binaries remain unsigned/not notarised — Gatekeeper asks
for a one-time "Open Anyway" approval
(guide).

Verify downloads: shasum -a 256 -c SHA256SUMS
Issues: https://github.com/ajsap/mailferry/issues
Author: Andy Saputra andy@saputra.org · Licence: GNU AGPL v3.0

MailFerry v2.0.1 — IMAP Migration & Sync

Superseded release

This version contains known issues that have been resolved in v2.0.3. Users should upgrade to the latest stable release. This release is retained for historical and reproducibility purposes.

Upgrade: MailFerry v2.0.3 — latest stable release

---

MailFerry v2.0.1 — Patch Release

High-Performance Native IMAP Migration Engine.

Patch release on top of v2.0.0: the terminal-state restoration
guarantee.

Fixed

• Terminal restoration is now a provable invariant. MailFerry
  captures the exact terminal state before the TUI starts (both the
  migration dashboard and mailferry attach) and restores it verbatim
  on every return path — including TUI startup failures and hard-stop
  timeouts — with idempotent defensive resets (primary screen, visible
  cursor, mouse reporting off, attributes reset). A PTY-level termios
  matrix across nine exit paths (completion, instant re-run, graceful
  Ctrl+C, double Ctrl+C, SIGTERM, SIGHUP, --dry-run, attach quit and
  attach Ctrl+C) verifies that no path can leave the shell with the
  "stair-step" newline artefact, raw input, or hidden echo.

No engine, protocol, state or data-handling changes: migration
behaviour is byte-identical to v2.0.0. Existing mailferry.db and
mailferry.toml are fully compatible.

macOS note: binaries remain unsigned/not notarised for now — Gatekeeper
will ask for a one-time "Open Anyway" approval
(guide).

Verify downloads: shasum -a 256 -c SHA256SUMS
Issues: https://github.com/ajsap/mailferry/issues
Author: Andy Saputra andy@saputra.org · Licence: GNU AGPL v3.0

MailFerry v2.0.0 — IMAP Migration & Sync

Superseded release

This version contains known issues that have been resolved in v2.0.3. Users should upgrade to the latest stable release. This release is retained for historical and reproducibility purposes.

Upgrade: MailFerry v2.0.3 — latest stable release

---

MailFerry v2.0.0 — Stable Release

High-Performance Native IMAP Migration Engine.

The complete native Go rewrite of MailFerry, published as the stable
v2.0.0 after three release candidates and a full internal release gate:
data integrity, idempotency, multi-process coordination, dry-run
zero-mutation and dedup-safety verification all passed on the exact
source commit this release was built from.

One static binary per platform — no Python, no imapsync, no runtime
dependencies. MailFerry never expunges or deletes mail during
migration, in any mode.

Everything in v2.0.0

• Native IMAP engine — streaming FETCH→APPEND, LITERAL+,
  STARTTLS/SSL, COMPRESS=DEFLATE, watchdogs, per-host budgets
• Bubble Tea TUI + headless parity — live dashboard, ten F1–F10
  views, automatic TTY detection, --no-tui, graceful shutdown
• SQLite State Database — per-message commits, resumable,
  duplicate-free adoption, ack-lost APPEND reconciliation,
  native per-OS locations, lazy creation, mailferry.db canonical
• Self-healing — stall detection, Recovery Mode, progressive
  isolation, persistent Failed Message Registry, COMPLETED WITH
  WARNINGS
• Multi-instance — shared State Database, atomic claiming, leases,
  heartbeats, automatic takeover, clear "Mailbox already active"
  reporting (verified with real OS processes, incl. kill-9 reclaim)
• Whole-file CSV validation — every error in one pass; canonical
  src*/dst* columns; obsolete v1 headers rejected with a rename hint
• --dry-run — mutating IMAP commands blocked inside the client
  before any byte reaches the wire (proven: zero mutations observed)
• ISO 8601 date-range migration — --from/--to, inclusive,
  INTERNALDATE-authoritative, persisted window, deterministic resume
• mailferry dedup — analysis by default; --execute is
  reversible (quarantine move / \Deleted flag, EXPUNGE never
  issued); strong multi-factor matching; interruption-safe
• mailferry attach — read-only live monitor of running
  migrations; never disturbs workers
• --portable — self-contained layout beside the executable
• Zero-side-effect informational commands · restrictive 0700/0600
  permissions · credential redaction everywhere

Notes

• macOS: binaries are not yet Developer-ID signed or notarised —
  Gatekeeper will ask for a one-time "Open Anyway" approval
  (guide).
  This does not indicate malware; signing/notarisation is planned.
• Linux amd64 was runtime-tested end-to-end; the other five targets are
  cross-compiled from the same verified source (macOS arm64 previously
  runtime-tested by the maintainer during the RC programme).
• Upgrading from rc.2/rc.3: existing mailferry.db and mailferry.toml
  are fully compatible — schema changes are additive; nothing to
  delete or migrate.

Verify downloads: shasum -a 256 -c SHA256SUMS
Issues: https://github.com/ajsap/mailferry/issues
Author: Andy Saputra andy@saputra.org · Licence: GNU AGPL v3.0

MailFerry v2.0.0-rc.3 — IMAP Migration & Sync

MailFerry v2.0.0-rc.3 — Release Candidate

High-Performance Native IMAP Migration Engine.

This is the final planned Release Candidate of MailFerry v2.0.0 —
the complete rewrite of MailFerry from Python to Go. It exists to gather
real-world testing before v2.0.0 is declared production-ready.

This is a pre-release, not the latest stable version. v1.0.0
(Python) remains the last stable release. Test carefully and keep your
source mailboxes until you have verified results. MailFerry never
expunges or deletes mail on either server, in any mode.

Highlights of the Go rewrite

• Native standalone binaries — one static executable per platform;
  no Python, no Perl, no imapsync, no external runtime. macOS
  (Apple Silicon + Intel), Linux (amd64 + arm64), Windows (amd64 + arm64).
• Native IMAP engine — pipelined streaming FETCH→APPEND with bounded
  memory, LITERAL+, STARTTLS/SSL, COMPRESS=DEFLATE, watchdogs, per-host
  connection budgets.
• Bubble Tea + Lip Gloss TUI — live dashboard plus nine more views on
  F1–F10 (digit aliases for SSH/tmux), detail popups, search, follow-mode
  logs, pause/retry controls, graceful-shutdown dialog; automatic TTY
  detection with a --no-tui headless mode driving the same engine.
• SQLite state management — per-message commit protocol (pure Go, no
  CGO); resumable and duplicate-free; ack-lost APPEND reconciliation.
• Self-healing — stall detection, connection recovery, Recovery Mode
  with progressive failed-message isolation, persistent Failed Message
  Registry, COMPLETED WITH WARNINGS semantics.
• Multi-instance clustering — shared State Database, atomic mailbox
  claiming, automatic takeover from offline workers.

New in rc.3 — multi-instance hardening

• Concurrent multi-process operation is first-class: several
  MailFerry processes safely share the canonical mailferry.db
  (unique run/worker identities, WAL, busy timeouts, atomic claiming,
  leases, heartbeats). Held mailboxes are reported plainly —
  Mailbox already active: … owned by worker … (run …) — never
  processed twice, and taken over automatically when released or when
  their owner dies (verified with real OS-process tests, including
  kill‑9 reclaim and exactly-once delivery under contention).
• No silent exits: runs that copy nothing say why; headless runs
  stream coordination events; every exit path restores the terminal
  (second-Ctrl+C and engine-panic paths fixed).
• Canonical src/dst CSV format — srchost,…,dstpassword; the v1
  old*/new* header is rejected with a clear rename hint.

Carried from rc.2

• Native OS-standard application paths, resolved centrally and
  created lazily:
  macOS ~/Library/Application Support/MailFerry/ · Linux XDG
  ($XDG_CONFIG_HOME, $XDG_STATE_HOME, $XDG_CACHE_HOME) · Windows
  %APPDATA%/%LOCALAPPDATA%. Precedence: CLI flags → mailferry.toml →
  native default.
• mailferry.db is the canonical per-user State Database (replacing
  the ./migration.db working-directory default). An old development
  ./migration.db is detected and reported with explicit choices —
  never silently adopted or duplicated.
• Zero-side-effect informational commands: --help, version,
  about, changelog, roadmap, config paths create nothing — no
  configuration, directories, logs or database. Configuration is
  generated on the first operational run or explicitly via
  mailferry config (regression-tested).
• Correct canonical slogan: High-Performance Native IMAP Migration
  Engine — enforced by an automated identity test.
• Restrictive file permissions (0700 directories, 0600 config/DB/logs
  where the platform supports POSIX permissions).
• Go-native documentation: rewritten README and CONTRIBUTING, new
  end-user macOS installation guide
  (docs/INSTALLATION-MACOS.md).

Known limitations (please test and report)

• Not implemented yet (planned for final v2.0.0): deduplication
  mode, date-range migration (--from/--to), mailferry attach,
  --portable mode.
• macOS binaries are not Developer-ID signed and not notarised —
  Gatekeeper will ask for a one-time Open Anyway approval on
  downloaded binaries. Expected for this RC; see the
  macOS installation guide.
  Never disable Gatekeeper.
• Clustering and COMPRESS=DEFLATE are automated-suite-tested and still
  under real-world validation (--compress off is the conservative
  fallback while diagnosing).
• Windows console support is cross-compiled with limited interactive
  testing.

Install & verify

Download the binary for your platform, verify its checksum against
SHA256SUMS, make it executable, and run mailferry version — it must
report MailFerry v2.0.0-rc.3.

shasum -a 256 -c SHA256SUMS      # sha256sum -c on Linux

Issues and feedback: https://github.com/ajsap/mailferry/issues
Author: Andy Saputra andy@saputra.org · Licence: GNU AGPL v3.0

MailFerry v2.0.0-rc.2 — IMAP Migration & Sync

MailFerry v2.0.0-rc.2 — Release Candidate

High-Performance Native IMAP Migration Engine.

This is the first published Release Candidate of MailFerry v2.0.0 —
the complete rewrite of MailFerry from Python to Go. It exists to gather
real-world testing before v2.0.0 is declared production-ready. (An
earlier internal candidate, rc.1, was superseded by this build before
public release; its content is documented in the changelog.)

This is a pre-release, not the latest stable version. v1.0.0
(Python) remains the last stable release. Test carefully and keep your
source mailboxes until you have verified results. MailFerry never
expunges or deletes mail on either server, in any mode.

Highlights of the Go rewrite

• Native standalone binaries — one static executable per platform;
  no Python, no Perl, no imapsync, no external runtime. macOS
  (Apple Silicon + Intel), Linux (amd64 + arm64), Windows (amd64 + arm64).
• Native IMAP engine — pipelined streaming FETCH→APPEND with bounded
  memory, LITERAL+, STARTTLS/SSL, COMPRESS=DEFLATE, watchdogs, per-host
  connection budgets.
• Bubble Tea + Lip Gloss TUI — live dashboard plus nine more views on
  F1–F10 (digit aliases for SSH/tmux), detail popups, search, follow-mode
  logs, pause/retry controls, graceful-shutdown dialog; automatic TTY
  detection with a --no-tui headless mode driving the same engine.
• SQLite state management — per-message commit protocol (pure Go, no
  CGO); resumable and duplicate-free; ack-lost APPEND reconciliation.
• Self-healing — stall detection, connection recovery, Recovery Mode
  with progressive failed-message isolation, persistent Failed Message
  Registry, COMPLETED WITH WARNINGS semantics.
• Multi-instance clustering — shared State Database, atomic mailbox
  claiming, automatic takeover from offline workers.

New since the rc.1 build

• Native OS-standard application paths, resolved centrally and
  created lazily:
  macOS ~/Library/Application Support/MailFerry/ · Linux XDG
  ($XDG_CONFIG_HOME, $XDG_STATE_HOME, $XDG_CACHE_HOME) · Windows
  %APPDATA%/%LOCALAPPDATA%. Precedence: CLI flags → mailferry.toml →
  native default.
• mailferry.db is the canonical per-user State Database (replacing
  the ./migration.db working-directory default). An old development
  ./migration.db is detected and reported with explicit choices —
  never silently adopted or duplicated.
• Zero-side-effect informational commands: --help, version,
  about, changelog, roadmap, config paths create nothing — no
  configuration, directories, logs or database. Configuration is
  generated on the first operational run or explicitly via
  mailferry config (regression-tested).
• Correct canonical slogan: High-Performance Native IMAP Migration
  Engine — enforced by an automated identity test.
• Restrictive file permissions (0700 directories, 0600 config/DB/logs
  where the platform supports POSIX permissions).
• Go-native documentation: rewritten README and CONTRIBUTING, new
  end-user macOS installation guide
  (docs/INSTALLATION-MACOS.md).

Known limitations (please test and report)

• Not implemented yet (planned for final v2.0.0): deduplication
  mode, date-range migration (--from/--to), mailferry attach,
  --portable mode.
• macOS binaries are not Developer-ID signed and not notarised —
  Gatekeeper will ask for a one-time Open Anyway approval on
  downloaded binaries. Expected for this RC; see the
  macOS installation guide.
  Never disable Gatekeeper.
• Clustering and COMPRESS=DEFLATE are automated-suite-tested and still
  under real-world validation (--compress off is the conservative
  fallback while diagnosing).
• Windows console support is cross-compiled with limited interactive
  testing.

Install & verify

Download the binary for your platform, verify its checksum against
SHA256SUMS, make it executable, and run mailferry version — it must
report MailFerry v2.0.0-rc.2.

shasum -a 256 -c SHA256SUMS      # sha256sum -c on Linux

Issues and feedback: https://github.com/ajsap/mailferry/issues
Author: Andy Saputra andy@saputra.org · Licence: GNU AGPL v3.0

MailFerry v1.0.0 — IMAP Migration & Sync

First stable release of MailFerry — High-Performance Native IMAP Migration
Engine.

Added

• Native asyncio IMAP protocol core: pipelined commands, streamed message bodies
  (constant memory), non-synchronising literals (LITERAL+), wire
  compression (COMPRESS=DEFLATE), STARTTLS and implicit TLS with
  certificate verification on by default, inactivity and byte-progress
  watchdogs, capability-driven optimisation with --baseline fallback.
• Migration, sync and backup in one command: fresh migration, fingerprint
  adoption of destinations pre-synced by other tools (duplicate-free,
  even after State Database loss), and incremental top-up runs; deletions
  are never propagated; optional --sync-flags re-applies flag changes.
• Per-message State Database (SQLite WAL): planned/inflight/done/skipped
  states, source→destination UID mapping via APPENDUID, UIDVALIDITY-aware
  re-verification, crash-window reconciliation, mailbox leases,
  import-state migration from the legacy wrapper, compact maintenance
  command.
• Scheduler: worker pools, per-host connection budgets, parallel folder
  pipelines inside large mailboxes, throttle-aware backoff; authentication
  failures are never auto-retried.
• Folder planner: NAMESPACE/delimiter translation, special-use role mapping
  (localisation-proof), Gmail virtual-folder policy, mUTF-7 Unicode names,
  include/exclude globs, explicit --map file.
• Live Dashboard: alternate-screen differential renderer, two-line MailFerry
  banner, global progress (messages/data %, throughput, ETA, duplicates
  prevented, reconnects, retries), per-mailbox operation verbs and detailed
  Source Server / Destination Server panels; non-TTY status lines;
  --json-progress snapshots.
• Reporting: session log, per-mailbox logs, results.csv, end-of-run
  summary, optional NDJSON event logs, --trace protocol logging with
  credential redaction.
• CLI: run, check (write-nothing preflight), init, import-state,
  capabilities, verify, compact; --version, --about, --help;
  exit codes 0/1/130/141.
• Tooling: single-source version and identity (mailferry/__init__.py),
  release builder with branding/header/changelog/license validation and
  SHA-256 checksums, AGPL source-header applier, end-to-end fake-IMAP test
  suite (34 checks).
• Packaging: standalone mailferry.pyz (zipapp), source archive, wheel.