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Netscape Communicator (.snm)

.snm file signature | application/octet-stream

The SNM format is a mailbox folder file used by Netscape Communicator, originally developed by Netscape Communications Corporation. It was used to store email messages and related folder data in Netscape Mail and other compatible internet suite applications. The format is now obsolete and may be encountered only in older user profiles or archival data; it generally poses little security risk beyond the usual caution required when opening legacy files.

Safe

Magic Bytes

Offset 0
00 1E 84 90 00 00 00 00

Sources: Gary Kessler

Extension

.snm

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .snm files in Python

Python 
def is_snm(file_path: str) -> bool:
    """Check if file is a valid SNM by magic bytes."""
    signature = bytes([0x00, 0x1E, 0x84, 0x90, 0x00, 0x00, 0x00, 0x00])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .snm files in Node.js

Node.js 
function isSNM(buffer: Buffer): boolean {
  const signature = Buffer.from([0x00, 0x1E, 0x84, 0x90, 0x00, 0x00, 0x00, 0x00]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .snm files in Go

Go 
func IsSNM(data []byte) bool {
    signature := []byte{0x00, 0x1E, 0x84, 0x90, 0x00, 0x00, 0x00, 0x00}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

GET /api/v1/snm
curl https://filesignature.org/api/v1/snm

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .snm file?

A .snm file is a Netscape Communicator file. The SNM format is a mailbox folder file used by Netscape Communicator, originally developed by Netscape Communications Corporation. It was used to store email messages and related folder data in Netscape Mail and other compatible internet suite applications. The format is now obsolete and may be encountered only in older user profiles or archival data; it generally poses little security risk beyond the usual caution required when opening legacy files.

What are the magic bytes for .snm files?

The magic bytes for Netscape Communicator files are 00 1E 84 90 00 00 00 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .snm file?

To validate a .snm file, read the first bytes of the file and compare them against the known magic bytes (00 1E 84 90 00 00 00 00) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .snm files?

There is no officially registered MIME type for .snm files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .snm files?

Netscape Communicator (.snm) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.