MSF File Extension
Thunderbird Mail Summary File
Overview – What is MSF File
The MSF files denoted by the extension .msf, is the Mail Summary File of Thunderbird emails. It only contains the headers and the summary of emails.
Thunderbird stores the mails in two files—one that holds the actual mail (MBOX File) and the other that holds the index of that particular mail. This index file is referred as the MSF file.
The main function of this file is to make sure that the other applications import mail from the MBOX file without any extension.
Application Category
Email related data files
Organization
Mozilla Foundation
Technical Specifications
File Signature Details
2F 2F 20 3C 21 2D 2D 20 3C 6D 64 62 3A 6D 6F 72 6B
Unique header identifying the Mozilla Mork index structure.
Location of MSF File
Windows Vista / 7 / 8 / 8.1
C:\Users\Username\AppData\Roaming\Thunderbird\Profiles\ xxxxx.default
Windows XP / Server 2003
C:\Windows\Application Data\Mozilla Thunderbird\Profiles\xxxxx.default
Windows 95 / 98 / ME
C:Documents and Settings\user\Local Settings\Application Data\Microsoft\Outlook
Application Supported
How to open and view MSF file
MSF file can be easily viewed using Thunderbird application. This file stores index details; hence, it is automatically configured by Thunderbird each time it is used.