Thunderbird is the popular email client which is available for all major platforms. It is an open source client which has MBOX as the main file format to which emails and other mailbox functionality data resides.
Along with MBOX, Thunderbird also has MSF and SBD file formats which serve different function for the email client.
MSF file is Mail Summary File which contains email headers and other information except body or content of an email.
MSF files are also associated with EarthLink E-mail Message File (EarthLink Inc.), Multiple Sequence File, Netscape Mail Summary File (Netscape) and SeaMonkey along with Mozilla Thunderbird. The latest addition in this list is the Eudora 8 version.
Thunderbird creates two types of files in the user profile directory which are as follows:
MSF file location in Thunderbird can be checked from the below steps:
There are some situations in which the user receive attachment in email containing MSF files and most of the times not able to open them due to unfamiliarity of the file format.
Opening MSF Files - In Windows if the user double click the MSF file extension, then Windows ask to “Open with” response and if a dedicated application is already installed then only the MSF file can be opened otherwise not.
MSF files can be opened in the Windows if the user has Thunderbird email client or Netscape web browser.
This will help the user in locating MSF files on the system and opening MSF using Thunderbird application. If you also want to open mailbox files in Thunderbird, you can use the free ImportExportTools add-on for this task. However, if email migration to other email client is involved, then go for a professional Thunderbird to Outlook Converter.