+1 (855) 418-2323
File ConvertersAn MSG file is a single Microsoft Outlook item saved to disk: an email message, a contact, an appointment or a task. Outlook creates it when you drag a message to a folder or use File > Save As. MSG files open natively in Outlook for Windows. Without Outlook, use a free MSG viewer or convert the file to EML, PDF or HTML.
What is an MSG file?
MSG stands for Outlook Message. Microsoft documents the structure in the MS-OXMSG specification. Internally, an MSG file is a Compound File Binary container, the same OLE2 structure that old Word .doc files use. Inside it, every piece of the message is stored as a separate MAPI property: subject, sender, recipient lists, dates, flags, the body in plain text, HTML and RTF variants, plus attachments and embedded messages as nested storages.
| Property | MSG file |
|---|---|
| Extension | .msg |
| Developer | Microsoft |
| File type | Compound File Binary (OLE2) with MAPI properties |
| Created by | Outlook for Windows: Save As, or drag and drop to a folder |
| Contains | One message, contact, appointment or task with all properties and attachments |
| Encoding | Unicode (modern Outlook) or ANSI (legacy) |
| Opens with | Outlook, Mail Viewer, Outlook Viewer, MSG converters |
Because the file is a complete copy of the item, including attachments, headers and read flags, MSG is the standard way to hand over individual emails in legal discovery, HR cases and IT audits. A folder of MSG files preserves everything an Outlook mailbox knew about those messages, even after the mailbox itself is deleted.
MSG vs EML: what is the difference?
EML is the other common single-message format. An EML file is plain MIME text, the same format mail servers exchange, so Thunderbird, Apple Mail, Windows Mail and even a text editor can read it. MSG is binary and tied to Outlook’s MAPI property model. Classic Outlook for Windows saves messages only as MSG and offers no EML export; most other clients do not import MSG. If you need to move messages between the two worlds, convert them. The full comparison is in EML vs MSG. Whole-mailbox archives are different formats again: PST on Windows and OLM on Outlook for Mac. And a message that arrives as a single smime.p7m attachment is not an MSG file at all but an S/MIME envelope; see the P7M guide.
How do I open an MSG file?
- Outlook for Windows. Double-click the file. Outlook opens it in a message window with attachments intact, even if the account it came from no longer exists.
- Without Outlook, on Windows. Install the free CoolUtils Mail Viewer. It lists MSG and EML files in a folder, shows the message with headers and attachments, and prints or saves it. Outlook Viewer does the same for whole PST and OST mailboxes. Both are free for home use.
- On a Mac, Linux or a phone. Convert the file to EML with the MSG to EML online converter, then open the EML in Apple Mail, Thunderbird or any mail app. Or convert it to HTML and read it in a browser.
More options, including Gmail and Windows Mail workarounds, are collected in 11 ways to open an MSG file without Outlook.
How do I convert an MSG file to PDF?
Converting MSG to PDF is the standard way to file an email as evidence or attach it to a report, because the PDF keeps the header block, the body and the list of attachments in one fixed layout.
- One file, no installation: upload it to the MSG to PDF online converter and download the PDF. Free, no registration.
- Hundreds of files: Total Mail Converter converts a folder of MSG and EML files to PDF, DOC, TXT, HTML or TIFF in one batch on Windows. It can combine all messages into one multipage PDF, keeps attachments as files next to the output, and runs from the command line. The 30-day trial is free and needs no card or email; a Personal license starts at $59.90. Total Mail Converter Pro also renders the attachments themselves (DOCX, XLSX, images) inside the same PDF.
- From Outlook itself: open the message and use File > Print > Microsoft Print to PDF. Attachments are not included.
For a Word document instead of a PDF, use MSG to DOC online or choose DOC as the target in Total Mail Converter.
Frequently asked questions
How do I open a MSG file?
Double-click it if Outlook for Windows is installed. Otherwise open it in the free CoolUtils Mail Viewer, or convert it to EML, HTML or PDF online and open the result in any mail client, browser or PDF reader.
Can you open a MSG file without Outlook?
Yes. Mail Viewer and Outlook Viewer from CoolUtils open MSG files on Windows for free. On other platforms, convert the MSG file to EML with the online converter and open it in Thunderbird, Apple Mail or Gmail.
Can you convert a MSG file to PDF?
Yes. The MSG to PDF online converter handles single files in the browser. Total Mail Converter converts whole folders of MSG files to PDF on Windows, with the option to merge them into one document.
How do I convert a MSG file to Word?
Upload the file to the MSG to DOC online converter, or run Total Mail Converter with DOC as the output format. The message header, body and attachment list are written into an editable Word document.
What is the difference between MSG and EML?
MSG is Outlook’s binary format built on MAPI properties; EML is plain-text MIME used by almost every other mail client. MSG stores more Outlook-specific data, EML is far more portable. Converters translate in both directions.
