Oe E.mails

[davidanthony]

A few days ago, my On Bo content became substantially edited. At the same time, headings in the In Box drop downs 'today' 'last week' ' two weeks ago ' and ' older' appeared all with a limited number if incoming messages in them. Where have the rest of my e.mails gone, and more importantly, how can I retrieve them.
They are not in Junk, Deleted or Archive In Box