A couple of (or more) enterprising folks have built an interface that integrates with Windows Explorer and Gmail. The end result is a drive that shows up on the user’s explorer window. All the users need to do is to drag and drop files into this drive. This ultimately mails these files to the user’s gmail account. My understanding of this utility is that it is pretty safe, but, don’t take my word for it. I love using it to backup my files. I used to use FTP sites, but find this so much more convenient. You can download it from here.