Question on browser inside "sandboxie" and download to save an e-mail attachment?

Snow,

Yes, one of the purposes of Sandboxie is to keep things isolated... so that, if you accidentally downloaded a virus, it would be trapped inside the sandbox [rather than infecting your actual system].

RIGHT-click on the Sandboxie icon in your system tray, select SHOW WINDOW, the SANDBOX tab, DEFAULT BOX, SANBOX SETTINGS.   On the left, click on the + sign by RECOVERY, to expand that to reveal QUICK RECOVERY.   You should see several file locations listed there... possibly including DOWNLOADS, DOCUMENTS, FAVORITES, and/or DESKTOP (although I believe some of yours may be different).    You can add other folders of your choice.   These "Quick Recovery" files indicate the primary areas where you WANT Sandboxie to really save files to your disk.

With this is mind, go back to your e-mail and see if you can direct the download of your photo attachment into one of those particular files.   When you do, you should see a popup from Sandboxie, indicating that the file is eligible for recovery, meaning that it can be moved out(side) of the sandbox.   I typically tell it to recover to the same folder (on my real system, as it was tyring to save-in inside the sandbox).   And click the RECOVER button.   If you get that far, it should do the trick.

There may be other ways to do this... but this method works for me.

Also (now that you know where the settings are), there should be a setting to ask you whether to empty the sandbox's contents when you exit the program... and this too should let you know that you have lingering files there that will be lost unless saved.  

EDIT:  In fact, I just closed down my sanboxed browser, withOUT having QUICK-RECOVERED a file... and I'm getting a DELETE CONTENTS screen from Sandboxie, again reminding me that I can still recover the file [or else, delete the Sandbox's contents].   Admittedly, it's been a while since I set up the program, so I don't recall if this was a default option, or something I tweaked.

EDIT2:   There is a short tutorial for using Sandboxie http://www.sandboxie.com/index.php?GettingStarted , which if you have the time, elaborates on this (in parts 4 and 5 of the tutorial).