Netscape Communicator e-mail or News messages index
File type: Internet related file
A snm file is an index used by Netscape Communicator for an e-mail folder or a News folder.
It helps Netscape Mail locate and display messages; it is not the mailbox containing the complete message text.
File type category:
Internet related file
Date updated: October 11, 2026
Record marked as obsolete and not updated for a long time.
The snm file extension is associated with Netscape Mail, the e-mail client included with Netscape Communicator, version 6 and earlier. Netscape Mail was used to send and receive e-mail messages.
An snm file contains a saved index of e-mail or News messages. The index stores information that the client uses to display a folder, such as message listings and status information. The actual messages are stored separately in the corresponding mailbox or News files.
This format was used by the Microsoft Windows version of Netscape Mail. Netscape Communicator and Netscape Mail are obsolete, so new software generally does not create or use these index files.
Open the related e-mail or News folder in the original Netscape Mail or Netscape Communicator installation on Microsoft Windows. The program normally reads the snm file automatically when it opens the corresponding folder; the file is not intended to be opened as a standalone document.
If the original software is unavailable, the index alone is usually not useful. Keep it together with the corresponding mailbox or News files when attempting to recover the messages.
An snm file is an index rather than a complete message archive, so it cannot be meaningfully converted into an e-mail document by itself.
To preserve the messages, open the corresponding mailbox in Netscape Mail and export or migrate the messages using an e-mail program that supports the mailbox data. The original mailbox files, not just the snm file, are required.
Software applications that handle other tasks involving snm files:
Microsoft Windows
Netscape Mail
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