FAQ

Is InboxFerry safe? Will it modify my mailbox?

No. InboxFerry is read-only by design. It opens your mailbox folders with IMAP EXAMINE (not SELECT) and fetches message content using BODY.PEEK (not FETCH BODY). It never sends STORE, EXPUNGE, or APPEND commands to the source server. Your mail is never touched.

Does InboxFerry upload my email anywhere?

No. Everything stays on your computer. InboxFerry connects directly from your machine to your IMAP server — nothing passes through any intermediate server, there is no telemetry, and there is no cloud sync of any kind.

What format does InboxFerry use for backups?

mbox — the standard Unix mailbox format. mbox files are plain text, portable, and supported by Thunderbird, Apple Mail, grep, and virtually every mail tool built in the last 40 years. You can read your backup without InboxFerry if you need to.

InboxFerry also supports Maildir as a migration source and can copy mail directly from one IMAP server to another.

Which email providers work with InboxFerry?

Any standard IMAP server, including:

• Gmail (requires an App Password; OAuth2 supported)
• Outlook and Microsoft 365
• Fastmail
• iCloud Mail
• Yahoo Mail
• Self-hosted servers: Dovecot, Courier, Cyrus, and others

If your provider supports IMAP (and most do), InboxFerry can connect to it.

What is the difference between Backup and Migration?

Backup downloads your mail to your computer as mbox files. The result is a local archive you own and control.

Migration copies mail from one IMAP server to another — for example, from Gmail to Fastmail. No local mbox file is created; messages are uploaded directly to the destination server.

Direct download vs Mac App Store — which should I get?

Direct download gives you the latest version as soon as it is released, uses a simple license key for activation, and has no sandboxing restrictions on which folders you can write to.

Mac App Store is convenient if you prefer App Store updates and purchase management through your Apple ID. The sandboxed environment may restrict access to certain folders outside your home directory.

Both editions are functionally equivalent for most users.

What happens after 1 year of updates?

Your license continues to work indefinitely — there is no expiry date. The 1-year period only affects which new versions you can install: updates released within 12 months of your purchase are included; updates released after that require a new purchase. Existing customers receive a discount.

Why is InboxFerry not a subscription?

A local backup tool that runs on your machine has no ongoing server costs. A subscription would mean you are renting access to something you already own. InboxFerry is a one-time purchase: you buy it, you keep it.