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. A batch tool to
convert MSG to EML handles a whole folder without opening Outlook.
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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