This site allows users to send large files to other users easily. The problem with sending large files through email is that most mail servers will not accept such huge attachments. The idea is not to send the files directly to the recipent, but to provide a link for the recipent to download. So basically what happens is the user uploads the file to Sendspace and once the upload is completed, Sendspace will send an email to the recipent with the download link. It is just that simple. Sendspace allows a maximum of 300MB file size. They also ensure that the file is secure for their users.