Open a MSG file — no Outlook needed
Drop one Outlook .msg file — or a folder full of them — and read them here as a single list. Message text, attachments, and headers, parsed on your own machine with nothing uploaded.
How do I open a MSG file without Outlook?
Use a reader that understands the container, because a .msg is not text: it is a CFBF compound file — a miniature filesystem of streams — where every field of the message is a separately stored, typed MAPI property. Mailward walks that structure in your browser: the file is parsed locally in a Web Worker, nothing is uploaded, and reading, attachment saving, and batch-opening a folder of .msg files as one searchable list are free, on macOS, Windows, Linux, or ChromeOS. Two format quirks worth knowing. First, the stored sender is often an Exchange X.500 distinguished name (/O=ORG/OU=…) rather than an email address — the real SMTP address sits in a different property, and a good viewer shows you that one. Second, only messages that actually arrived from the internet carry a header block; a .msg saved from a sent folder never had one, so no tool can show headers that were never recorded. One stated limit: S/MIME-signed content stays sealed inside its smime.p7m wrapper.
Drop one .msg file, or select a whole batch — all read locally.
Read the message text and save any attachments, free.
Check the headers of received messages, including the routing chain.
Search across every opened message by sender, subject, or text.
Open a MSG file — no Outlook needed
A .msg file is one Outlook message saved as its own file — dragged out of Outlook onto the desktop, attached to another email, or produced by an export tool. Only Outlook for Windows opens them natively; a Mac, a Chromebook, or a PC without Office is stuck.
Mailward parses the format itself in a Web Worker in your browser: drop one file or a whole batch (they merge into one searchable list, free), read the text, save the attachments, and inspect the headers of received messages. Nothing is installed and the files never leave your device.
What is actually inside a .msg file
A .msg is a CFBF compound file — the same container format as old Office documents — holding a miniature filesystem of storages and streams. Every field of the message lives in its own stream, named after a MAPI property tag: the subject in one, the sender in another, each recipient and each attachment in its own sub-storage. Reading one means walking that tree and decoding typed properties, not scanning text.
Two properties trip people up. The sender address stored in a .msg from a corporate mailbox is frequently an Exchange X.500 distinguished name — a long /O=ORG/OU=… string, not an email address; the usable SMTP address lives in a separate property, and Mailward prefers it wherever it exists. And the internet header block is only present on messages that arrived from outside: a .msg saved from your own sent folder never had headers to begin with, so their absence is a fact about the message, not a parsing failure.
Older Outlook installations wrote ANSI-variant files whose strings are encoded in a Windows codepage that the file only hints at. Mailward reads the message's codepage and locale properties and re-decodes with the matching encoding, which is the difference between a readable Japanese subject line and a row of mojibake. One honest limit: S/MIME-signed messages store their content inside a smime.p7m envelope that requires the cryptographic layer to open — the wrapper is visible here, the signed payload is not.
- Container
- CFBF/OLE2 compound file — storages and streams of MAPI properties
- Written by
- Outlook for Windows (drag out, Save As, or automation)
- Sender field trap
- Often an Exchange X.500 DN — the SMTP address is a separate property
- Headers
- Present only on received messages; sent items never had them
- ANSI variants
- Codepage inferred from message properties — non-Latin text decodes correctly
- Not supported
- S/MIME-signed content (visible only as its smime.p7m wrapper)
Comparing formats? PST, OST, OLM, MBOX & EML explained — what each one is internally, and what is lost converting between them.
Before you trust a mail file to a website
Q. What is a .msg file?
A single Outlook item — usually an email — saved as a standalone file in Microsoft's compound-file format, with the message stored as typed properties rather than as plain text. Drag a message out of Outlook and a .msg is what you get.
Q. Can I open .msg files on a Mac?
Yes — that is the main reason this page exists. The parsing runs in your browser, so macOS, Windows, Linux, and ChromeOS all work, with no Outlook and nothing installed.
Q. Can I open many .msg files at once?
Yes, free — select a batch and they merge into one list you can browse and search as a set. Opening a separate archive alongside (a PST next to your .msg batch, say) is the Pro step.
Q. Are signed or encrypted messages supported?
Not meaningfully. An S/MIME-signed .msg stores its real content inside a smime.p7m wrapper, which needs the cryptographic layer to unpack — you will see the wrapper attachment, not the message. We would rather say that here than have you find out mid-investigation.
Free to open, read, search, and export one message. Batch conversion is a one-time $19 licence — no subscription, no recurring fees.
Other formats & archives
Same local-first engine, every common mail format.