Glossary
What Is an MSG File?
An MSG file is Microsoft Outlook's format for a single saved email. It is a binary file that bundles the whole message, the sender and recipients, the subject, the body with its formatting, and any attachments, into one self-contained file. Outlook creates an MSG when you drag a message to your desktop or save it to disk.
TL;DRMSG is Outlook's container for a single email, attachments and all. Convert it to PDF when you need to open or archive the message without Outlook.
What an MSG File Holds
Unlike a plain-text email file, an MSG packs a full message plus Outlook-specific data:
- The header fields: from, to, cc, subject, and the date sent.
- The body in plain text, HTML, and Outlook rich text.
- Every attachment, embedded inside the same file.
- Outlook metadata such as read status, categories, and flags.
Because an MSG is a binary Outlook format, double-clicking one on a computer without Outlook usually does nothing. The file is fine; the machine simply has no program that understands the format.
Why Outlook Uses MSG
Saving a message as MSG keeps a pixel-perfect copy outside the mailbox, with formatting and attachments intact. People use it to archive important emails, attach a full message to another email, or hand a record to colleagues and legal teams, all without exporting an entire mailbox.
MSG holds one message; PST holds a whole mailbox. If you need to save many emails at once, exporting to a PST is faster than saving each message as its own MSG file.
MSG Versus EML
MSG is Outlook's proprietary binary format, while EML is a plain-text standard that almost every mail client can read. EML travels better between programs; MSG preserves Outlook-specific details. If you need a saved email to open outside the Microsoft world, EML or PDF is the safer container.
How to Open or Convert an MSG File
To read or archive an MSG without Outlook, convert it to a universal format. A batch converter turns a folder of MSG files into PDF, keeping the layout, headers, and attachments, so each message opens on any device and stays easy to file, search, and share.
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