What is a .MSF file?
MSF is a Thunderbird mail-summary index in the Mork format.
- Did you know
- The MSF index lets Thunderbird show a folder without re-reading every message.
- The Mail Summary File is a Mork database, a quirky near-text format named after the character Mork from the sitcom “Mork & Mindy”.
- Mork was invented at Netscape by David McCusker, and Thunderbird still uses it for folder summaries, though its address book moved to an SQLite-backed store around version 102.
- What Analyser reads
- Identify and read more email, calendar and contact files: Outlook for Mac archives (.olm) and templates (.oft), S/MIME .p7m/.p7s, Mozilla Mork stores (.msf/.mab), Eudora/Outlook Express mailboxes (.mbx/.toc), phone backups (.vmg SMS, .vnt notes), XML/JSON iCalendar and vCard (.xcal/.jcal/.xcard/.jcard), LDIF (.ldi) and legacy address books (.pab/.wab/.abbu).
- Depth of analysis
- .MSF is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .MSF file
- Drag a .MSF file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.