Given the lack of control of MIME type flagging in most email clients, it can be
helpful to use indicative suffixes e.g .txt on text files, to avoid them being
flagged as yours was "application/octet-stream", although many apps (e.g file)
still seem to struggle with files using UTF-8 for some reason.

--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in binary units and prefixes, physical quantities in SI.]