The Mail-in-a-Box alternative
built for production.
Mail-in-a-Box gives you a one-command personal email box on a single Ubuntu VPS. Vectis Mail is API-first, multi-domain mail infrastructure for teams and SaaS — a self-hosted transactional sending API and inbound webhooks alongside your mailboxes, declarative YAML config, and atomic updates with health-gated rollback. Same instinct for owning your own mail, built to run in production.
At a glance
Side-by-side, current as of July 2026.
| Vectis Mail | Mail-in-a-Box | |
|---|---|---|
| Target user | Teams, SaaS, multi-domain operators | Individuals, families, single-org |
| Mail stack | Postfix · Dovecot · Rspamd | Postfix · Dovecot · SpamAssassin |
| Deployment model | Docker Compose | One-command shell script (OS-native) |
| Supported OS | Linux (Ubuntu, Debian, RHEL family) with Docker | Ubuntu 22.04 LTS only (fresh install) |
| Install difficulty | Guided installer, ~20 min | One command, ~15 min |
| Configuration model | Declarative YAML + vectis apply | Web control panel · no config-as-code |
| REST API | 40+ endpoints (sending, webhooks, domains, mailboxes, analytics) | Minimal admin API only · no sending API |
| Transactional sending API | Yes — domain-scoped keys, batch, attachments | No — SMTP submission with mailbox creds |
| Inbound webhooks | Yes — HMAC-signed, retry-with-backoff | No |
| Antispam (default) | Rspamd (modern heuristics) | SpamAssassin |
| Multi-domain | Built-in: many domains on one install | Single-org-shaped |
| Per-domain analytics | Yes (Pro) | No |
| Webmail | Roundcube | Roundcube |
| Calendar / contacts (CalDAV/CardDAV) | Not yet (Phase 4 roadmap) | Yes (Nextcloud-based) |
| Update model | Atomic 6-phase orchestrator with auto-rollback | Re-run setup script (fragile if box modified) |
| Observability built in | Prometheus-format metrics + alerts; Grafana/Loki optional | Logs only · bring your own stack |
| License | Business Source License 1.1 (auto-Apache 2.0 after 4y); commercial Pro license | CC0-1.0 (public domain) |
| Pricing | $0 Starter · $39 USD/tenant/month Pro (unlimited installs) | $0 forever · donations welcome |
Why teams move to Vectis Mail
Where a one-command personal box stops being enough.
- You're running mail for a team or SaaS, not a single person or family.
- You need a real REST API and inbound webhooks alongside mailboxes: a SendGrid-shape sending API that you host yourself.
- You manage multiple domains and need real multi-domain hosting, not single-org constraints.
- You want declarative config: one
config.yamlplusvectis apply, not click-through a web panel. - You want orchestrated updates with automatic rollback, not a re-run-the-setup-script model.
- You want Rspamd's modern heuristics out of the box.
- You're running on something other than Ubuntu 22.04 (Debian, Ubuntu 24.04, RHEL family).
One honest scope note: Vectis Mail doesn't yet ship bundled CalDAV/CardDAV calendar and contacts (it's on the Phase 4 roadmap). If groupware calendar/contacts are central to your daily use, factor that gap into your plan — pair Vectis Mail with a dedicated CalDAV/CardDAV service for that lane.
How they differ
Different products for different audiences
Mail-in-a-Box's README is explicit: "no user-configurable setup options."That's the value proposition. The project deliberately optimises for a one-command personal email box over flexibility — a deliberately narrow scope. Vectis Mail is built for the wider job: production infrastructure you can operate, automate, and scale across domains and teams.
Vectis Mail sits in a different category. The audience is teams, SaaS, and multi-domain operators who need a real transactional sending API, inbound webhooks, multi-domain hosting, and config-as-code. Comparing the two on the same table is useful for the migration question, but understand what each product is for.
API surface
Mail-in-a-Box exposes a minimal REST API for control-panel operations: creating users, managing aliases, setting forwards. There's no transactional sending API, no inbound webhooks, no domain-scoped keys, no per-domain rate limiting. SMTP submission is the only programmatic send path.
Vectis Mail has 40+ endpoints covering sending (single + batch with attachments), inbound webhooks (full body parsing, HMAC-signed payloads, exponential-backoff retry), mailbox/alias/domain CRUD, analytics, audit logs, and admin operations. Domain-scoped API keys with per-domain rate limits make Vectis usable as a real transactional service: a SendGrid-shape API that you self-host.
See the API Reference for the full surface.
Multi-domain hosting
Mail-in-a-Box is single-org-shaped. You can run multiple domains on one box, but the control panel, the user model, and the operational shape all assume one organisation. Vectis Mail hosts many domains on one install, each isolated at the domain level — its own DKIM keys, analytics, and spam controls. If you're running mail for multiple brands or customer subdomains, that's a structural difference, not a config tweak.
Configuration model
Mail-in-a-Box's configuration lives in the web control panel and on-disk files managed by the install script. There's no declarative config surface. Every change is a UI click or a manual file edit, and the upgrade path documented as "fresh OS only"means modifying the box voids the supported upgrade story.
Vectis Mail uses a single config.yaml as the source of truth.vectis apply diffs the desired state against running state, regenerates affected service configs (Postfix, Dovecot, Rspamd, Traefik), and reloads only what changed. Terraform, Ansible, or your own automation can manage Vectis Mail declaratively via the same REST endpoints the CLI uses.
Update + rollback
Mail-in-a-Box upgrades by re-running the setup script: straightforward when the box is unmodified, fragile when you've customised anything. There's no automatic snapshot, no health-check gate, no rollback. If a release breaks something, recovery is whatever you do manually.
Vectis Mail's orchestrator runs a 6-phase pipeline:
- Snapshot — Postgres dump + Compose backup taken before any change.
- Migrate — forward-only SQL migrations applied with row-level locking.
- Pull — new container images pulled and verified.
- Deploy — services recreated with the new images.
- Health-check — Postfix, Dovecot, Rspamd, API, Traefik all probed for liveness + actual mail-handling readiness.
- Complete — change locked in, snapshot retained for the rollback window.
Any phase failure triggers automatic rollback to the snapshot. SeeInstallation for the full update model.
Calendar + contacts
Mail-in-a-Box bundles Nextcloud for CalDAV and CardDAV; calendar and contacts work out of the box. Vectis Mail doesn't ship calendar/contacts yet; that's on the Phase 4 roadmap. If you actively use CalDAV/CardDAV, that's our most significant functional gap today — plan to pair Vectis Mail with a separate CalDAV/CardDAV service until Phase 4 lands.
License + pricing
Mail-in-a-Box is CC0-1.0: public domain, the most permissive license possible. Zero lock-in, zero strings, no commercial edition, no paid support, donations welcome.
Vectis Mail is dual-licensed: BSL 1.1 for the core (free Starter: up to 3 domains, 25 mailboxes per domain, full API, webhooks, monitoring, backups) and a commercial Pro license at $39 USD/tenant/month (unlimited domains and mailboxes, per-domain analytics, OIDC SSO, priority support, one subscription covers unlimited installs). Seepricing.
Migrating from Mail-in-a-Box to Vectis Mail
The mail-data layer migrates cleanly (both products are vanilla Postfix + Dovecot). The calendar/contacts and control-panel-config layers need manual export.
- Stand up Vectis Mail on a fresh VPS following the installation guide. Configure your domain(s) but leave DNS pointed at Mail-in-a-Box for now.
- Sync mailbox data with
imapsyncordoveadm backup— same Dovecot underneath, maildir transfers directly. - Generate new DKIM keys on Vectis Mail and publish them to DNS alongside the existing Mail-in-a-Box keys. Run both in parallel during the switchover.
- Export Roundcube settings (per-user filters, signatures) from Mail-in-a-Box Roundcube and re-import into Vectis Mail Roundcube.
- Re-create domains, mailboxes, aliases, and forwards via Vectis Mail's CLI or API. The Mail-in-a-Box control panel doesn't export config-as-code, so this is a manual transcription.
- Export Nextcloud calendar + contacts to iCal/vCard if you use them. Vectis Mail can't import these — you'll need a separate CalDAV/CardDAV destination from this point. This is the most significant step if calendar is part of your daily use.
- Cut DNS over: update MX to point at the Vectis Mail server. Mail starts flowing through Vectis Mail as DNS propagates.
- Verify + decommission: watch logs for a few days, then decommission Mail-in-a-Box.
Realistic timeline: an afternoon for a small personal install without calendar, longer if Nextcloud calendar/contacts are central to your use.
Frequently asked questions
Is Vectis Mail a drop-in replacement for Mail-in-a-Box?
Not 1:1 — the two products target different scopes. Mail-in-a-Box is a single-server, single-org, one-command personal email box. Vectis Mail is API-first, multi-domain mail + transactional sending built for teams and SaaS running production infrastructure. The mail-data layer (Postfix + Dovecot) migrates cleanly via standard IMAP sync, so the switch is a normal migration rather than an export fight. Once you need a real REST API, inbound webhooks, or genuine multi-domain hosting, Vectis Mail is the natural next step.
Does Mail-in-a-Box have a sending API or inbound webhooks?
Mail-in-a-Box exposes a minimal REST API for control-panel operations (creating users, managing aliases) but not a transactional sending API and not inbound webhooks. SMTP submission with mailbox credentials is the only programmatic send path, and inbound mail lands in mailboxes only. Vectis Mail ships 40+ REST endpoints covering sending (single + batch with attachments), inbound webhooks with HMAC signatures, mailboxes, domains, analytics, and admin operations.
Can I run Mail-in-a-Box on something other than Ubuntu 22.04?
No — Mail-in-a-Box explicitly targets fresh Ubuntu 22.04 LTS only. No Debian, no Ubuntu 24.04, no RHEL family, no BSD. Modifying the install or running it on anything else voids the upgrade path. Vectis Mail runs on any Linux that supports Docker — Ubuntu (22.04+ or 24.04), Debian, and RHEL-family hosts are all production-tested.
Will I lose my calendar and contacts if I migrate?
Calendar and contacts on Mail-in-a-Box live in its bundled Nextcloud install (CalDAV/CardDAV). Vectis Mail doesn't yet ship CalDAV/CardDAV (it's on the Phase 4 roadmap), so you'd export to iCal/vCard before tearing the old box down and re-import wherever you keep calendar from then on. If calendar and contacts are central to your use, that's a real cost to factor into your migration plan.
Try Vectis Mail
Production mail + transactional API for teams and SaaS. Multi-domain, declarative, observable.
Other Vectis Mail alternatives
Coming from a different stack? Read the comparison that matches it.
vs Mailcow →
Same self-hosted stack, declarative YAML config, REST API, atomic updates with rollback.
vs iRedMail →
Compared with the long-running OS-native open-source mail stack: REST API, declarative YAML, Rspamd by default.
vs SendGrid →
Same API surface, no per-email pricing. Flat $0–$39/mo covers unlimited sending volume.
vs Postmark →
Flat $0–$39/mo self-host vs the developer-loved transactional SaaS. Same API, mailboxes included.