Blog
News, updates, and ideas from the team behind Mbox Viewer — the native Mac and Windows app for opening MBOX and EML email archives.
- emlformatswindows
EML vs MSG: What They Are and How They Differ
An .eml file is one email in plain MIME text, readable anywhere. A .msg file is the same message in Outlook's binary format, plus properties that never left Outlook. Which one you get, and when the difference bites.
Read - announcementproductmboxshell
mboxShell 1.0: The First Stable Release, and Everything Since 0.8
mboxShell, our open-source terminal tool for MBOX files, reaches 1.0 with a config file that finally does what it says. Here is that, plus what came in the four releases we never wrote about: Maildir export, a security review, a light theme, Aruba mailboxes and numbered exports.
Read - pstthunderbirdformats
How to Convert Outlook PST to MBOX Without Paying for a Converter
You do not need to buy a PST converter. Thunderbird and the free ImportExportTools NG add-on turn an Outlook PST into standard MBOX in four steps, and there is a command-line route for an orphan PST.
Read - announcementproductmacos
Mbox Viewer 2.9.0: Safer, Faster and Easier to Use With a Screen Reader
A release built from a review of 2.8.6 on four fronts: security, performance, usability and accessibility. Plus Malay, Finnish and Hebrew, for 21 languages. On the Mac App Store and the Microsoft Store since 25 September.
Read - mboxformatsarchives
Where Do Attachments Go Inside an MBOX?
Attachments live inside the message itself, encoded as base64 text in a MIME part. That is why the file is so big, why searching for words in a PDF finds nothing, and why one old format lost its attachments entirely.
Read - mboxthunderbirdgmail
A Thunderbird MBOX and a Gmail MBOX Are Not the Same File
Both are valid MBOX and both open in the same reader, but they are organized on opposite principles: folders versus labels, one file per folder versus one file for everything, and deleted mail that is still in there.
Read - mboxarchivesproduct
How to Find One Email Among 500,000
Searching a huge archive is not about better keywords — it is about narrowing on the things the archive knows for certain: who sent it, when, and whether it had an attachment. A practical method, with the syntax.
Read - mboxproductarchives
How to Choose an MBOX Viewer: Seven Checks to Run Yourself
Seven checks you can run before paying for an MBOX viewer: your own file at full size, the original's timestamp, the network off, the second open, a real search, the way out — plus the honest alternatives.
Read - gmailbackuparchives
Your Gmail Account Is Gone. The Takeout Still Opens.
A closed, suspended or deleted Google account takes the mail with it — unless somebody exported it first. A Takeout MBOX needs no account, no password and no internet connection to open.
Read - mboxmacosformats
Apple Mail's .mbox Is a Folder, Not a File
Export a mailbox from Apple Mail and you get a folder called Inbox.mbox with a file named mbox inside it. That file is the standard MBOX; the folder is Apple's packaging. Here is how to open either one.
Read - mboxformatsarchives
MBOX to PDF, Without a Converter
Turning emails from an MBOX archive into PDFs is an export, not a conversion: open the mailbox, pick the messages, save them as PDF with headers intact. No upload, no second copy of your archive.
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How to Open a 50 GB MBOX File
Big MBOX files don't crash readers because they are corrupt — they crash them because most readers load the whole file into memory first. What a streaming parser and an index change, with real numbers.
Read - mboxprivacyarchives
Is It Safe to Open an MBOX File?
An MBOX file is plain text and cannot execute anything by itself. The real risks are elsewhere: attachments you save and open, remote images that report back to the sender, and readers that upload your archive to a server.
Read - announcementproductmacos
Mbox Viewer 2.8.6 for Mac and Windows: Gmail Labels Stop Being a Wall of Rows
Nested Gmail labels now fold into a tree instead of a flat wall of near-identical rows, the annual subscription is back next to the lifetime licence, and Privacy can forget what you have opened. On the Microsoft Store since 4 September and the Mac App Store since the 7th, plus 2.8.7 for Windows.
Read - thunderbirdmboxarchives
Where Thunderbird Keeps Your Email
Thunderbird stores every folder as an MBOX file with no extension, inside a profile folder your system hides. Here is where to find it on Mac, Windows and Linux — and how to read that mail without Thunderbird installed.
Read - mboxformatspst
MBOX Converter: When You Actually Need One
Most people searching for an MBOX converter want to read their mail, not convert it — and converting makes a second copy of an archive they already have. Here is when conversion is genuinely the answer, and what to convert to.
Read - mboxmacoswindows
Nothing Happens When You Double-Click an MBOX File
Double-clicking a .mbox file does nothing on Windows, and on a Mac it hands the file to Apple Mail, which tries to import it. Here is why neither system knows what to do with your mailbox, and how to fix it in a minute.
Read - mboxgmailarchives
How Do You Work With an MBOX File?
You asked Google for your data, waited days, and got a file you cannot open. Here is what to actually do with an MBOX file: read it, search it, pull messages out of it, and keep it somewhere it will survive.
Read - historylegacymbox
Eudora: The Email Client of the Early Internet, and How to Read Its Mail Today
Steve Dorner wrote it in 1988 and named it after a short story. Qualcomm sold it to eighteen million people. It died in 2006, and in 2018 the Computer History Museum published its source code under a BSD licence. If you still have a Eudora folder on an old disk, its mail is in mbox — and it opens today.
Read - mboxformatsarchives
What Is an MBOX File?
An MBOX file is a plain-text file holding many email messages one after another, each starting with a line that begins "From ". It is what Google Takeout hands you when you export Gmail — and what Thunderbird and Apple Mail keep your mail in.
Read - announcementproductmacos
What's Inside Your Google Takeout? A Free Mac App That Tells You
Ten ZIP files of twenty gigabytes each, and no idea what is in them. Takeout Reports opens a Google Takeout archive and reports what it holds — how many messages, how many photos, which years, which services came back empty — without unzipping it and without touching the network.
Read - educationproductmacos
MBOX archives for schools and organizations: the edition you buy in Apple School Manager
Apple School Manager buys apps, not in-app purchases. That is why Mbox Viewer Pro for Education exists: a Custom App that arrives unlocked, bought by the seat and deployed by MDM.
Read - thunderbirdmboxarchives
How to Split Large Thunderbird Mailbox Files Without Losing Emails
A Thunderbird folder is a single mbox file, and after fifteen years it can weigh more than the disk it started on. Here is how to cut one into smaller mailboxes — with Mbox Viewer or with mboxShell, our open-source terminal tool — and, more importantly, how to prove afterwards that not a single message was lost.
Read - announcementproductwindows
Mbox Viewer for Windows 2.8.4 and 2.8.5: Exporting a Selection, and Printing That Finally Says Who Wrote
Two updates in two days on the Microsoft Store: 2.8.4 exports your selection as a new MBOX and doubles the free plan to 1 GB; 2.8.5 fixes printing, which had been leaving out the subject, the date and the sender since the very first version.
Read - announcementproductmacos
What's New in Mbox Viewer 2.8.4 for Mac: Hand Over Only What Has To Be Handed Over
Version 2.8.4 exports your selection as a brand-new MBOX, doubles the free plan to 1 GB and brings an edition for schools and universities. On the Mac App Store since 23 August.
Read - announcementproductmacos
What's New in Mbox Viewer 2.8.2: Merging Mailboxes, Rebuilt
Version 2.8.2 for Mac and Windows is all about merging mailboxes: Apple Mail exports are traceable again, the merge finally tells you what it is doing, and the toolbar explains itself. Still strictly read-only.
Read - announcementproductmacos
What's New in Mbox Viewer 2.7.0: Faster, More Private, More Accessible
Mbox Viewer 2.7.0 is a big reliability, privacy, accessibility and speed update — faster on large mailboxes, stronger tracking-pixel blocking, full VoiceOver and keyboard support, and rock-solid handling of huge or malformed files. Still strictly read-only.
Read - formatsmboxpst
A Field Guide to Email Storage Formats: History, Anatomy and a Comparison
How email is actually stored on disk — MBOX, Maildir, EML, PST, OST, OLM, MSG, NSF and historical formats like Eudora. Their history, how they're built, what each one is good for, and a side-by-side comparison.
Read - mboxemlformats
MBOX, EML, PST, OLM: Email Archive Formats Explained
What's actually inside an email archive? A plain-language tour of the four formats you'll meet — MBOX, EML, PST and OLM — and how to read each one on a Mac.
Read - mboxarchiveslegacy
Reading Old Email Archives from Eudora, Entourage and Other Classic Clients on a Modern Mac
That backup from Eudora, Entourage, Netscape or PowerMail is probably standard mbox — which means a modern Mac can still read it. Here's how to find out and open it safely.
Read - backupgmailprivacy
Why You Should Back Up Your Gmail Locally (and How)
Cloud email is convenient until it isn't. Here's why keeping a local Gmail backup matters — account lockouts, accidental deletion, leaving providers — and how Mbox Viewer makes that archive usable.
Read - announcementproductmacos
Introducing Mbox Viewer: Open Any MBOX or EML File, Instantly
Why we built Mbox Viewer — a native macOS app that opens MBOX and EML files of any size with streaming performance, total privacy, and no Electron or Java in sight.
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