Mission Critical Email

Zimbra Migrations Made Easy

Zimbra migration software
Migrates to & from
every Zimbra build

Zimbra-to-Zimbra migration software

Any version 8.8.15 or higher. Any OS. Any Zimbra edition. All easily migrated — with the source left intact.

When a Rolling Upgrade or a system-to-system rsync just won’t do, our bespoke migration software moves a complete Zimbra system (or selected domains) onto fresh infrastructure — recreating every account, user setting, and mailbox on the destination in staged passes that keep users live on the source until a short, final cutover — all while the original system stays fully intact as your fallback.

Platform-independentFOSS ↔ Network Edition, any OS
Re-architect freelyChange server count & topology
Battle-testedRefined on real customer cutovers
Zero-risk sourceOriginal system left untouched

Built for the migrations that matter

Reach for our migration software when:
  • 01A Rolling Upgrade or an rsync migration isn’t appropriate — for example when S3 is present on the source system.
  • 02You bought a Network Edition license and need to migrate off an existing Open Source system.
  • 03You’re a Zimbra BSP partner onboarding a new customer’s to-be-retired self-hosted Zimbra system.
  • 04You need as short a cutover window as possible — staged premigration passes move the mail while users stay on the source, so the cutover itself is minutes, not days.
  • 05You’re a hosting provider absorbing customers in waves — domain-scoped licensing migrates one wave of domains at a time onto the same destination farm.
// Example migration
Source
Zimbra 9.0.0 FOSS
Ubuntu 18
→
Destination
Zimbra 10.1 NE
Rocky Linux 9
Different versions, different OS, FOSS → Network Edition — and a different number of servers in the same move. Our software does that.

How it works — a two-path architecture

SOURCE SYSTEM Existing Zimbra Any version · any OS FOSS or Network Edition Any number of servers LEFT INTACT MCE MIGRATION ENGINE PROVISIONING PATH Accounts · structure · settings IMAPSYNC PATH All mail, message-for-message DESTINATION SYSTEM New Zimbra New version · new OS New server topology READ WRITE

Provisioning recreates the full system — users, structure, and settings — while IMAPSYNC moves every message in parallel. The source is read, never altered, so you always have a clean rollback.

Certified across the Zimbra spectrum
Sales · Engineering · Admin · Gold VAR · Silver BSP · Instructor
Zimbra Sales Certified Zimbra Sales Engineer Certified Zimbra Gold Partner VAR Zimbra Silver Partner BSP Zimbra Certified Instructor Zimbra Training Partner Zimbra System Admin Certified

What migrates — the complete inventory

A whole Zimbra system… recreated — not approximated.

Developed over many months of continuous refinement across real customer migrations. Our software, working with IMAPSYNC, migrates a complete system – or selected domains – and leaves the source intact — just in case.

Infrastructure

  • Classes of Service with the full inheritance chain preserved. A name that already exists is restored as <name>_restored rather than overwriting, and affected domains/accounts are repointed.
  • Local domains & domain aliases, plus each domain’s default COS.
  • Per-domain DKIM keys — signed mail keeps verifying at cutover with no DNS change.
  • Distribution lists, their members, and DL aliases.
  • Resource accounts (e.g. conference rooms).
  • External / virtual accounts — off-domain users shared into internal folders or resources.

User accounts

  • Password, display / given / surname
  • Two-factor authentication — TOTP secret, scratch codes & app-specific passwords; users keep their authenticator, no re-enrollment
  • Email aliases; preferred From address & display name
  • Work title & company
  • Full address, ZIP, and telephone
  • Explicit per-account COS assignment
  • All account-level ACEs and the zimbraId
  • All Sieve scripts (filters)
  • Personal Amavis block / allow lists & Trusted Senders
  • Spell-check “words to ignore”
  • Out-of-office auto-reply settings — message, external-sender variant, active window
  • Mail forwarding — admin- and user-set forwarding addresses, with the local-delivery setting
  • Account status (locked, closed, maintenance…) — applied after the final mail sync, so a disabled account can’t block its own migration
  • Security-tightening CoS overrides — password locks, per-seat feature grants (EWS, S/MIME), quotas, session lifetimes; every one applied is logged for review

Mailbox content

  • All address books — every contact folder and subfolder, not just /Contacts, each exported individually with names preserved.
  • All calendars — every calendar folder and subfolder, not just /Calendar.
  • Briefcase and Tasks.
  • Email signatures.
  • RSS / URL feed folders — recreated with their feed URLs, ready to poll.
  • Folder shares — outgoing grants and incoming mountpoints, recreated in the correct dependency order. The complete share topology is preserved: shared calendar, contact, task, and briefcase folders are pre-created on the destination — even empty ones — so every grant lands.
All mail
Every share respected; every message copied by IMAPSYNC.
Folder sharing is handled accurately. IMAPSYNC migration scripts are created automatically with per-account folder exclusion lists. Folders User A shares to User B are only sync’d on User B’s mailbox. User A sees those folders’ contents when sharing is restored at the tail end of the migration. And repeat passes are delta-fast: a persistent sync cache lets the premigration runs do the heavy lifting while users stay on the source — the cutover pass moves only what’s new.
What does not migrate// by design
  • GALsync accounts.
  • ActiveSync, S/MIME, ZCO/EWS, NE Backup — NE-only features skipped on a Network Edition → FOSS move; no FOSS equivalent, and they would fail account creation. Two-factor authentication is the exception — it migrates.
  • Custom localconfig, MTA settings, SSL certs, branding, external auth (Okta / JumpCloud / AD) — these belong to the destination’s own build. Domains that authenticate against an external directory are detected and listed for you, so nothing is forgotten at cutover.
  • Policy-loosening account overrides — one-off exemptions from Class-of-Service policy (e.g. a 2FA opt-out) are surfaced for review, not silently carried; the security-tightening direction migrates automatically.
  • Domain-level ACEs — account-level ACEs do migrate.
  • Admin-role flags (zimbraIsAdminAccount / delegated) — intentionally not set; admins are exported for reference and reconstructed deliberately.
  • Per-domain public-service hostname / port / protocol — you set these on the destination, since they often change as a result of a migration.
Mission Critical Email
Licensing
$495
per migration
$7.85
per mailbox migrated
Volume discounts available above 2,500 mailboxes.
Schedule a migration.
sales@missioncriticalemail.com
Prep docs: github.com/LMStone510/mce-migration-preparations
Free & open-source: IMAP preflight, Broken Share Check & Remediation, License Count, and CoS Override Report scripts
Independent static code review of the migration software — in the same repo
Zimbra and the Zimbra logo are trademarks of Synacor, Inc.