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<http://www.aol.com/article/2015/08/01/how-to-see-if-your-emails-are-being-tracked-in-gmail-before-open/21216953/>
<http://www.aol.com/article/2015/08/01/how-to-see-if-your-emails-are-being-tracked-in-gmail-before-open/21216953/>