Updated 9 September 2026
What happens to a file
Your browser opens the file on your computer. Your emails and attachments are not uploaded. Messages, sender addresses, search terms and filenames are not sent to an analytics service or placed in page URLs.
Opening another archive, closing the workspace or reloading the page clears the application’s active archive state. The app does not store archives in local storage, a browser database or a cloud account. Your original file and any downloads you save remain on your computer.
What uses the network
Your browser requests this website and its code to load the application. Hosting infrastructure may process ordinary access information such as IP address and requested page. The site includes no third-party analytics, payment form, remote font or advertising integration. The application does not transfer email data over the network.
Reading an email safely
Messages are shown as text. Email scripts, styles, links and remote images are not activated by the viewer. Attachments are downloaded only when you request an export. This tool does not scan attachments for malware; opening a downloaded file is a separate action in your chosen software.
What may change in an export
MBOX separator lines are removed when optional source emails are extracted. Body quoting is kept as stored in the archive. MIME transfer encodings are decoded for attachment files; calendar text may be normalized by the parser. Generated paths distinguish duplicate names and neutralize directory information. Some potentially active extensions receive an additional .download suffix.
The JSON manifest retains index values; CSV text values have a visible text: prefix to reduce spreadsheet formula interpretation. Keep your original MBOX as the recovery source.
Current limits
- One MBOX file at a time, with no fixed total-file-size cap.
- Up to 100,000 messages and 100,000 attachments per archive.
- 64 MiB per raw message; up to 100 attachments per message.
- 256 KiB of headers per message, with bounded MIME nesting.
- Very large message or export indexes can exceed the metadata budget. The app stops with an error and asks for a smaller selection or archive.
- Long email body previews are shortened. Exported source messages are not shortened.
- Direct saving is available in supported desktop Chrome and Edge, with no fixed ZIP-size cap. Disk space and browser resources still apply.
- Standard ZIP downloads are limited to 200 MiB, including indexes and optional source emails.
- Email-list CSV downloads are limited to 64 MiB. They contain full metadata for the matching emails, including original and UTC dates, but no message bodies or attachment contents.
- Reading and export preparation can be cancelled. Once a direct save is finalizing, keep the tab open until it completes.
- Conventional separator-based MBOX only. Content-Length variants, encrypted mailbox recovery and recursive extraction of attached emails are not supported.
Direct saving asks you to choose a destination before export begins. The application writes the selected output there; it does not retain a hidden copy in a browser database. A failed or cancelled save must not be treated as a complete package. The manifest includes SHA-256 checksums of exported attachments to help compare bytes, not to certify an email’s sender or authenticity.
These are implementation limits, not guaranteed processing times or a promise of support on every device. Parsing stops on known unsupported or incomplete inputs. Ambiguous MBOX boundaries and malformed MIME can exceed what a reader can reliably detect; inspect the message count and output before relying on them.
Payments
No payment details are collected by the site. All current tools can be used without a purchase.