Free MBOX file viewer
Open MBOX mailbox files – such as Google Takeout Gmail exports, or Thunderbird and Apple Mail mailboxes – and browse the messages inside.
This tool runs locally in your browser, so even very large files open quickly and your email is never uploaded anywhere.
What is an MBOX file?
MBOX is a simple format that stores a whole mailbox in one file, with each message following the one before it. Google Takeout exports Gmail in MBOX format, and Thunderbird, Apple Mail and many other apps can import or export it.
Want to put messages back into a mailbox? Save them as .eml files here, then use our EML importer to add them to Gmail or Microsoft 365.
A free tool provided by Auth-Email
Auth-Email makes your Gmail, Outlook, or other OAuth 2.0 email account available to any IMAP, POP3, or SMTP email client — no app passwords or special configuration needed.
Frequently asked questions
What is an MBOX file?
An MBOX file stores many email messages one after another in a single file. Google Takeout exports Gmail as MBOX files, and apps such as Thunderbird and Apple Mail use or export the format.
Can I open large MBOX files?
Yes. The viewer reads the file in your browser in sections, so even multi-gigabyte Google Takeout exports can be browsed without uploading anything.