Nowadays, the most of webmail providers, such as Yahoo, Google and MS, provided a huge storage or even unlimited. Therefore, you will have a lot of email. Now, I got 11915 in my inbox at Yahoo and I have around a hundred new incoming email per day. This morning, I need to find an email which have some information I need but I got that email at the early of this year, maybe Jan or Feb(I can't remember). Well, email search is my life saver. I remember some keywords in email and I know the email received this year. I entered the keyword and limited this year. I can't find the exact emai. But I found an email with similar information. They are a kind of related. It should be received similar period of time. Then I got my inbox, went to the page has the email I found and I scrolled a page. Then I found the email I need. So, email with a search function, that is a "must have" function!