Streak, an email organization tool for Gmail that allows consumers to organize their inboxes on a chrome or safari browser, has released an update that lets users track who has opened their emails. The feature is delivered as a pop up message and tells the recipient that the message has been read. The tool allows also allows email recipients to know see when the email was read and on which device. The feature is free.
Email tracking is definitely getting a lot of attention these days! You should also check out ContactMonkey (www.contactmonkey.com). Free email tracking for Outlook, Gmail and fully integrated with Salesforce.com.
Happy tracking!