nospam writes:
If you want to remove the EXIF data (which also contains the thumbnail),
you can use Exifer:
http://www.friedemann-schmidt.com/software/exifer/

Exifer comes up with a 404 not found in the tucows link at bottom.

your original question was to save a valid thumbnail, not remove it.
that happens automatically when saving the photo.

if you want to remove it, then use exiftool.

I don't want to remove the EXIF thumbnail nor do I want to save it.
I only want to reset it to what the current cropped photo contains.
When I send someone that photo it contains that reset EXIF thumbnail.