.msg vs .eml: what is the difference?

.msg: Outlook's own format

Outlook for Windows saves emails as .msg files. Inside is a Microsoft compound file: the message, its details and its attachments, in Outlook's own structure. Outlook for Windows opens them; most other apps can't.

.eml: the standard format

.eml files follow the internet's standard for email, MIME. Gmail, Thunderbird, Apple Mail and many other apps save and open them.

Side by side

• Made by: .msg by Outlook for Windows; .eml by Gmail, Thunderbird and most other mail apps.
• Opens in: .msg in Outlook for Windows; .eml in most mail apps.
• Attachments: both keep them inside the file.
• Best for: .msg when everyone uses Outlook; .eml for sharing, as almost any app can open it.

For records, keep a PDF

For keeping or sharing, a PDF beats both: it opens everywhere, and it can't be changed by accident. Our tools turn .msg and .eml files into PDFs with their attachments, in your browser, so we never see your emails.