Dbinbox gives your Dropbox account a custom URL that anyone, whether they use Dropbox or not, can use to upload files to you. If you (or they) are still under draconian file attachment restrictions, or you just want to send yourself a file without using email to do it, Dbinbox does the trick.
Sure, you could just email a file to yourself, or have someone else email a file to you, but Dbinbox lets anyone upload a file directly to you, no matter what the file size or type is. That includes large files like movies and video that most corporate mail servers won't handle, or file types that you need to move but your mail provider may block (executables, for example). The dev explains it this way on his Github page:
By visiting your personal dbinbox url, non-Dropbox users will be able to upload files straight into a special inbox folder in your Dropbox.
This is also quite handy if you need to send yourself a file from someone else's computer but don't want to log into email or remember a tinyurl.
An answer to https://forums.dropbox.com/topic.php?id=3...
To use it, all you have to do is connect your Dropbox account to dbinbox at the link below. If you're worried about truly public uploads, you can protect your account with a password so only people who know it (or get it from you) can upload.