Gmail, as long as I can remember, has always displayed a paperclip icon next to the date/time of an e-mail indicating a file is attached to that particular e-mail. While the basic indicator of an attachment is great, it would be nice to have a heads up of what kind of file is attached, especially if you are expecting a specific type of document from someone. With a Chrome extension called Attachment Icons for Gmail, getting alerted to type of file attached is possible.
Visit the Chrome Web Store to install the extension; it's free and takes a matter of seconds to install.
Once the extension is installed, the paperclip icon is changed to a thumbnail representing the file type attached. The icon will be located next to the date/time in the far right, not next to the star icon as shown in the screenshots in the Web Store.
By installing Attachment Icons for Gmail, you'll be able to quickly identify if it's a PDF, MP3, ZIP, or any other common file type attached to your e-mail without even having to open it.
Sometimes the biggest improvements we make to our workflow are done by the smallest enhancements. This extension is one of those small enhancements.
(Via: Addictive Tips)