If I understand correctly, you're a service that uploads e-mail attachments to a central location? Kinda like sending all -mail attachments to google Drive, then sorting by who you send to?
I think that's a good problem to solve. Just a few minutes ago one of my coworkers walked over to another coworker's desk to explain a file they just uploaded to Dropbox.
The parallax effects on the front page aren't very smooth when scrolling though, and my personal opinion would be to have the Russia/English navigation item displayed as the last item rather than the first. Other than that, it looks great!