Gmail tops the list of mail service providers not due to a few reasons. Everything it introduces and facilitates its users is incredible. The activeness of billions of users itself proves the trust, authenticity and reliability factor of Gmail. In its 15 years of wonderful journey, Gmail has not only achieved several milestones but also provided a lot of convenience to end-users.  Apart from such trustworthiness, there are some areas where users have to face trouble while using Gmail. Lots of features and functions are not understood by the users, or they find some...