How to open an MBOX file
To open an MBOX file, drop it onto this page: SaveMail lists every message in the mailbox, lets you read each one with attachments, and saves any of them as PDF, all in your browser with nothing uploaded. If you want the mailbox inside a mail client instead, the steps for Thunderbird, Apple Mail, Outlook and Gmail follow.
Save as PDF opens your browser's print dialog: choose "Save as PDF" as the destination. Text in the PDF stays selectable and searchable.
Open an MBOX file in your browser
- Drop the
.mboxfile (from Google Takeout, Thunderbird or Apple Mail) into the box above, or click to pick it. - Wait for the list: SaveMail scans the file and shows every message by subject, sender and date. A mailbox with thousands of messages takes a few seconds.
- Click a message. It opens with the header block, the body, inline images and an attachment list.
- Download attachments one by one or as a ZIP, and press Save as PDF for a copy of the message.
The MBOX is read with the File API in this tab; it never leaves your computer and nothing is kept after you close the tab. MBOX files of a few hundred MB open; the limit is your browser's memory, so a desktop browser is the right place for a big Takeout export.
How to open an MBOX in Thunderbird
Thunderbird stores every folder as MBOX internally, so it is the natural client for one. Three ways:
- Import tool: open the menu, Tools, Import, choose Import from file, Mailbox file in mbox format, select the
.mbox, and Thunderbird creates a folder under Local Folders. - Import add-on: install an MBOX import/export add-on from Thunderbird's add-ons catalog, then right-click Local Folders and use its Import mbox file command. The same add-on exports folders back to MBOX.
- Manual copy: close Thunderbird, copy the file (without extension) into the Local Folders directory of your profile, restart; the mailbox appears as a folder.
Thunderbird builds an index on first open, so a large mailbox takes a minute to show. Once it is in, you can move messages over IMAP into any account, which is the standard way to get an MBOX into Gmail: MBOX to Gmail.
Import an MBOX into Apple Mail
- In Mail, choose File, Import Mailboxes.
- Select Files in mbox format and click Continue.
- Pick the
.mboxfile or the folder containing it, then Continue.
The messages appear under On My Mac in an Import folder, and you can drag them into any mailbox. Apple Mail exports the same way through Mailbox, Export Mailbox, which produces an .mbox package; other programs read the regular MBOX file inside it.
Can I import an MBOX into Outlook?
Not directly. Outlook's import wizard accepts PST and CSV, not MBOX, in every version including Outlook 365 and the new Outlook. The workarounds:
- IMAP bridge: import the MBOX into Thunderbird, add the same account Outlook uses (an Outlook.com or Microsoft 365 mailbox) to Thunderbird, and drag the folder into it. Outlook then syncs the messages from the server.
- Convert to PST: a desktop MBOX-to-PST converter writes a PST you open in Outlook with File, Open & Export, Open Outlook Data File.
- Just read it: if you only need to find and keep a few messages, open the MBOX above, save them as PDF and download their attachments; no Outlook needed.
Background on the format, including why Outlook uses PST instead: what is an MBOX file and what is a PST file.
Save MBOX messages as PDF, and the limits
Each message you open here can be saved as a text-based PDF through the browser's print dialog, with the From, To, Date, Subject and Message-ID header block intact, which is what a record needs. Attachments are separate downloads; keep them in the same folder. The Compact option trims quoted replies and signatures.
Honest limits: it is one PDF per message. For a mailbox of 300 messages that means 300 Save as PDF runs; a merged multi-message PDF is not offered. Encrypted messages display as encrypted. The tool does not edit messages, split the MBOX, or write EML or PST files. The mechanics in detail: MBOX to PDF.
Troubleshooting: MBOX will not open or shows odd messages
- The file has no extension: Takeout and Thunderbird sometimes deliver a bare file. SaveMail reads the content, not the name; mail clients may need you to add
.mbox. - Apple Mail's export is a folder named
Something.mbox: open it in Finder and use themboxfile inside. - Messages run together or split in odd places: the file breaks the "From " separator rules; try the import add-on in Thunderbird, which is tolerant of such files.
- The browser slows down: the file is very large. Use a desktop browser, close other tabs, or split the export into smaller labels in Takeout.
- A search for "update mbox android version" is about MBOX TV set-top boxes, not mailbox files; nothing on this page applies to them.
Frequently asked questions
How do I open an MBOX file in Thunderbird?
Use the menu, Tools, Import, Import from file, Mailbox file in mbox format, or install an MBOX import add-on and right-click Local Folders. The mailbox appears as a folder under Local Folders.
Can I import an MBOX into Outlook?
Not directly. Import it into Thunderbird and move the messages over IMAP into the account Outlook uses, or convert the MBOX to PST with a desktop converter and open the PST in Outlook.
How do I import an MBOX into Apple Mail?
File, Import Mailboxes, Files in mbox format, pick the file, Continue. The messages land under On My Mac in an Import folder.
How do I open an MBOX file without installing anything?
Drop it on this page. SaveMail lists the messages in your browser, lets you read each one with attachments, and saves them as PDF; nothing is uploaded.
How do I open a Gmail Takeout MBOX?
Unzip the Takeout archive, find the .mbox file inside, and drop it here or import it into Thunderbird. It is a standard MBOX with extra X-Gmail-Labels headers.
Can I open an MBOX on Android or iPhone?
The phone browser handles single EML and MSG files well; a large MBOX needs a desktop browser's memory. Copy the file to a computer and open it there.