Google Analytics is often used for tracking visits to web pages and mobile apps but the same analytics service can also be used for tracking your outgoing email messages in Gmail. You can add the Google Analytics tracking code to your Gmail messages and you’ll instantly know if your email message has been seen or opened by the recipient.This is like getting a read receipt for your email messages but, instead of cluttering your inbox with read receipts, the email open activity is automatically logged as an event in your Google Analytics.