Mailbox Taxi vs BitTitan MigrationWiz

Picking between Mailbox Taxi and BitTitan MigrationWiz usually comes down to two questions: where do you want the mail data to live during the move, and how do you want to pay for it. BitTitan has been a staple of Microsoft 365 migrations for years, with cloud-based orchestration and a polished MSP program. Mailbox Taxi is a newer desktop-first IMAP tool that keeps every byte on your own machine. Both are legitimate choices for different shaped jobs, and this comparison walks through where each one fits.

TL;DR — when to pick which#

Side-by-side comparison#

Where Mailbox Taxi wins#

There are three areas where Mailbox Taxi has a structural advantage over MigrationWiz, and they all come from the same root cause: it runs on your machine, not in someone else's cloud.

Data stays local#

Every message Mailbox Taxi moves goes directly from source IMAP to destination IMAP over a connection you control. No third party touches the mailbox content. For regulated industries — legal, healthcare, finance, public sector — this is often the only model that passes a data-protection impact assessment. With MigrationWiz, you are explicitly handing mail body content to a cloud processor, which is fine for most commercial work but is a non-starter for some compliance contexts.

One-time pricing instead of per-mailbox#

If you are migrating ten mailboxes once, the BitTitan model is cheap and easy. If you run migrations as part of your monthly bread-and-butter MSP work, those per-mailbox licenses add up fast. Mailbox Taxi's planned flat licensing means a busy MSP engineer can run hundreds of mailboxes a year on the same license. This is the same argument that drives shops to look at MigrationWiz alternatives in our list of the best email migration tools.

Pause, inspect, resume#

Mailbox Taxi treats every job as a resumable state on disk. You can stop a 50,000-message sync, reboot the laptop, change the throttle, and pick up where you left off without losing the duplicate-detection state. MigrationWiz can pause cloud jobs too, but the inspection loop ("which message failed and why, and can I rerun just that one?") tends to be faster on a local tool because the logs are right there.

Cross-provider IMAP work#

A typical MigrationWiz customer is doing M365 to M365, or Google Workspace to M365. Mailbox Taxi is built for the messier real-world IMAP mix — a holding company with Fastmail, Zoho, GMX, and a cPanel host all consolidating to one Microsoft 365 tenant. The provider matrix in Mailbox Taxi is narrower than BitTitan's, but it goes deeper on the IMAP quirks per provider.

Where BitTitan MigrationWiz wins#

It would be dishonest to write this as a hatchet job — there are real reasons MigrationWiz has been a market leader for over a decade.

Microsoft 365 tenant-to-tenant depth#

BitTitan's coverage of Exchange Online, SharePoint, OneDrive, Teams, and the surrounding M365 estate is genuinely more complete than Mailbox Taxi's. If your migration scope includes "and also move all the Teams chats and SharePoint sites," MigrationWiz is the better tool and Mailbox Taxi is not even pretending to compete. See our Office 365 migration guide for which scenarios stay simple email and which expand.

Project-level orchestration at thousands of mailboxes#

When you are coordinating a 5,000-seat cutover across multiple geographies, having the orchestration plane in the cloud is a feature, not a bug. Your engineers in three time zones can all see the same dashboard, the same throttle budget, and the same queue. A desktop tool needs more wrapping (shared logs, a central status board) to do the same job at that scale.

Calendar, contacts, and public folders#

Mailbox Taxi today is an IMAP mail tool. It does not move calendar events, contact lists, or Exchange public folders. BitTitan does, and if those are in your scope you cannot fill that gap with Mailbox Taxi alone. You would either pair Mailbox Taxi with a separate calendar/contacts tool or use BitTitan end-to-end.

Legacy platform coverage#

Lotus Notes. GroupWise. Old Exchange 2010. BitTitan can still connect to these systems. Mailbox Taxi will let you point at them only if they expose IMAP — which most of those legacy stacks do not, cleanly.

Pricing comparison#

BitTitan MigrationWiz

• User Migration Bundle: roughly $15 per user, includes mail, calendar, contacts, and OneDrive/SharePoint.
• Email-only license: roughly $12 per mailbox.
• Volume discounts kick in at several hundred mailboxes.
• Annual subscriptions and reseller pricing available through the BitTitan partner program.

Mailbox Taxi

• One-time desktop license, pricing not yet announced.
• Per-engineer or per-machine license model planned (not per-mailbox).
• No subscription required to keep using a migrated mailbox.
• Join the waitlist to get notified when pricing goes live.

Rule of thumb: if your annual migration volume is under ~50 mailboxes, BitTitan's per-seat model is often the cheaper option. If you are migrating hundreds or thousands of mailboxes per year, a flat-license desktop tool tends to win on total cost. We cover the math in detail in our complete email migration guide.

Decision framework — which fits which reader#

The MSP running monthly migrations#

You absorb mailbox moves into a fixed-fee MSP contract. Per-mailbox licenses come straight out of your margin. Mailbox Taxi wins here because the license cost amortises across all the work you do that month. The exception: if a single client is moving 2,000 mailboxes in one go and wants tenant-to-tenant SharePoint as part of the scope, that's a BitTitan job. We dig into this trade-off in our best tools for MSPs piece.

The internal IT lead at a 500-person company#

You are doing this once. You want it done in a weekend with a Microsoft partner watching your back. BitTitan is the more comfortable choice — the orchestration plane is already running, your partner already has a license, and you have one neck to wring if something goes wrong. Mailbox Taxi is workable but you would be the one driving it.

The compliance-led migration#

You work in legal, healthcare, or financial services, and your DPO has flagged that mail content cannot pass through a third-party processor. Mailbox Taxi is the answer because the data never leaves the connection between source and destination. BitTitan would require a vendor DPIA and a data-processing agreement, and may not pass review at all.

The mixed-provider consolidation#

A holding company has acquired four smaller businesses, each on a different mail platform — Gmail, Zoho, Fastmail, and a cPanel IMAP host. You need to move all of them into one M365 tenant over six months. Mailbox Taxi handles this kind of work natively and gives you per-provider throttling settings; BitTitan handles it too but at higher cost per mailbox.

Migration mechanics: how each tool actually moves mail#

A few operational differences are worth knowing before you commit either way.

Authentication#

Both tools support modern OAuth 2.0 for Gmail and Microsoft endpoints, and both fall back to app passwords or basic auth where the provider still allows it. MigrationWiz makes you set up the OAuth consent in their cloud app, which means you grant BitTitan's app permission on the source. Mailbox Taxi runs the OAuth flow locally, so the token sits on your machine and never leaves it.

Throttling and connection limits#

BitTitan's cloud will hit Microsoft Graph and Gmail API endpoints from BitTitan IP ranges. Sometimes that's faster (warm endpoints) and sometimes it's slower (shared throttle pools across all BitTitan customers in your region). Mailbox Taxi runs from your IP, so the throttle is yours alone — meaning your weekend migration is not competing with someone else's Monday-morning push.

Error handling and the messy 5%#

In every migration, roughly 95% of messages move on the first pass and 5% throw something interesting: Message too large for destination, Folder UTF-7 conversion error, OAuth2 token expired, Too many simultaneous connections. Both tools give you that 5% in a report at the end. The difference is the inspection loop. With Mailbox Taxi the logs are local and you can re-run a single mailbox without re-queuing the job. With MigrationWiz you tend to clone a project or use the retry queue, which is a longer round trip.

What about a hybrid approach?#

It is genuinely common to use both. Run BitTitan for the bulk M365 tenant move where calendar and SharePoint matter, and use Mailbox Taxi for the long-tail IMAP mailboxes the partner could not justify per-seat. We see this most often during acquisitions where one company is on M365 and the acquired business has three mailboxes on Fastmail and one on Zoho.

FAQ#

If you want a wider look at the field before you decide, the best Office 365 migration tools round-up covers six other contenders, and our Mailbox Taxi vs CodeTwo and Mailbox Taxi vs SkyKick comparisons are useful neighbours to this one.