Images go to Lenovo PhotoMaster because this is the way the software that is doing the scan configured to operate. Access the scanning utility and configure it so that files are stored in its database until you save them or delete them. You need to access the scanning application and check the settings. Make sure there is no other application associated with the files scanned through its interface. I recommend resizing the images you scan in order to send them through email.
You can use XnView for this particular procedure because the scans might have 600 DPI, therefore the cause to high file size.
Download XnView: http://www.xnview.com/en/
Install XnView then locate your images on your hard disk (Lenovo Photo Master is just a viewer) and open them with XnView. Go to Tools > Batch Processing then switch to Transformations > Resize.