Sorry for the inconvenience. We have tried to duplicate the problem but was not able to. We suspect it is some compatibility with your network or your computer. Could you try on a different computer? Anybody else have this kind of problems?

Does it happen with Outlook or the website? Please try webmail or Outlook resp.

Otherwise, please use DriveHQ FileManager instead of email attachment. It is more cnvenience using FileManager. You can create a group shared folder or synchronized folder.