Since both error messages seem to mention your temporary directory,
I suspect the problem lies in the fact that you have not saved
permanent copies of the photos before you send them, and the files
you're trying to send are "in use" by the programs with which you
are viewing them at the time, or perhaps by your internet browser.
First of all, the more traditional way of sending image attachments
is to open your email program, compose an email and then click on
the 'add attachment' symbol. This opens a dialog which has you
browse to a folder on your computer and select an image or more
that you want to attach.
To accomplish this, you would normally be done using Jasc or
Fast Stone, and you would have saved the image file to a storage
location on your hard drive, and locate it there with the dialog
for attaching it in the email.
If you are using a menu within Jasc or Fast Stone to send the
email from within the program, you can probably eliminate the
error you're getting by going to File -> Save as, and saving
a copy of the image you're viewing to a local folder you can
easily find in the attachment dialog later. I create a folder
named 'a', so it shows up alphabetically at the top of my drive
as C:\a and is easy to locate.
Once you've created a saved copy of the file, try emailing it
from within the program. This should eliminate the error message.
It's unclear how you happen to be using Jasc or Fast Stone to
view files in the temporary directory. It sounds like you're
using these as default viewers and browsing images in your
browser's cache. If that's the case, you may find it simpler
to use a more common method. If you come across an image on
a web page that you'd like to share with others, r-click the
image and select 'Save picture as', and save it onto your
hard drive (say, in the 'a' folder). Then find it there later
from the attachment dialog in your email program.
The only other reason I can see that you'd be viewing an image
with an address in a temporary folder is if you've made some
modifications to it, say in Jasc, and haven't saved a copy of
it elsewhere, in which case the modified image exists in your
temporary folder, and needs to be saved first, as I noted above.
If I'm way off base in understanding your question, or if you
have any questions about my response, don't hesitate to ask
for a Clarification.