You need to do a lot for improvement.
Everytime i choose a number of mails and delete them, the pop up message says that they are deleted, but not getting deleted. Soon they will come inserted in between. Why is it happening? It really irritates, due to which i stopped viewing mails itself. But, unfortunately one of my mail contact whom i am following for official reasons, and the mails gets accumulated and not followed up as there are unwanted mails piling up.