MSG Viewer (Open Outlook MSG Files)

Outlook saves dragged-out emails as .msg files, and without Outlook they are hard to open: a Mac, a phone or a Gmail user just sees an unknown file. This viewer reads the .msg inside your browser and shows the sender, recipients, date and subject, plus the text of the message. Attachments come out as downloadable files, including emails attached inside the email. You also get a safe HTML copy of the formatted message and, optionally, an .eml file for any other mail program.

How to use this tool

1. Choose the .msg file.
2. Read the header fields and the text body below.
3. Download attachments one by one or all together as a ZIP.
4. Open "Message as HTML" to see the formatted email, or the .eml in your mail program.

Formula

.msg = OLE compound file → property streams (__substg1.0_XXXXYYYY) → subject 0037, sender 0C1A/5D01, To 0E04, body 1000, HTML 1013, compressed RTF 1009, attachments 3701/3707

A .msg file is a compound file of MAPI properties (MS-OXMSG). Text is UTF-16 or the code page the message names, such as 949 for Korean, 932 for Japanese or 1252 for Western. Many Outlook messages keep their HTML only inside compressed RTF; the RTF is decompressed (MS-OXRTFCP) and the HTML inside it recovered (MS-OXRTFEX). Plain rich-text messages are offered as an .rtf file. The HTML copy has scripts and event handlers removed, and remote pictures (tracking pixels) are blocked, while pictures stored in the message are shown. Attached Outlook items become .eml files.

Example

A forwarded Invoice March.msg from Outlook on Windows shows: From Kim Minji <minji@example.co.kr>, To Accounts, Date 2026-03-04 01:12 UTC, Subject FW: Invoice March. It has 2 attachments, invoice-0304.pdf (184 KB) and an attached email that comes out as Original order.eml. "Message as HTML" shows the formatted body with its embedded logo.