Before ios7, you could search for an email using the search function and have a decent chance finding it. With ios7, it became nearly impossible to locate an email by sender because the search function searched every part of the email (even other recipients) and flagged every email that included a reference to that person (again, even when that person is just a recipient of the email). And it seemed to come up with multiple versions of the same emails (which were always the ones I don't want). I couldn't figure out how to sort out the irrelevant ones.