You can use application/octet-stream for unknown types.
RFC 2046 states in section 4.5.1:
The “octet-stream” subtype is used to
indicate that a body contains
arbitrary binary data.
You can use application/octet-stream for unknown types.
RFC 2046 states in section 4.5.1:
The “octet-stream” subtype is used to
indicate that a body contains
arbitrary binary data.