If the Send To > Mail Recipient missing when you right-click on a JPG image file, you can fix it with these registry modifications:
[HKEY_CLASSES_ROOT\.jpg]
@="jpegfile"
"PerceivedType"="image"
"Content Type"="image/jpeg"
[HKEY_CLASSES_ROOT\.jpg\OpenWithProgids]
"jpegfile"=hex(0):
[HKEY_CLASSES_ROOT\.jpg\PersistentHandler]
@="{098f2470-bae0-11cd-b579-08002b30bfeb}"
[HKEY_CLASSES_ROOT\.jpg\UndoClass]
@="jpegfile"