For example, in the Search box he'll type 'Bob' so he can find all emails that Bob sent him.  When he does the search, it will only return emails from Bob going back a couple of months.  However, if you search the inbox manually by sorting using "From", and look at all the emails sent by Bob there are emails that date back years.  So, why is the search function only returning recent emails and not all the emails?

Thanks in advance!

LG