Once you have updated you Dropbox for Chrome extension it will let you :

Easily send large files. Just click the Dropbox icon in the compose window, select files or folders, and click Insert Link(s). No waiting for uploads to complete, no file size limit, and no eating up space in your inbox. Say goodbye to zip files. Attach folders and multiple files instantly, without having to zip files up. Send files to anyone. Even if they don’t have Dropbox or the extension, recipients can see and download the attachments you send them. Quickly save files sent to you. Add files to your Dropbox with a click so you can access them anywhere.

Dropbox users can now save files sent to them right to the Dropbox, without needing to download and upload them onto your account first. You can download the updated version of the extension from the Chrome Web Store.