Help Change Email settings to show ALL e-mails?


So I have 2 gmail's and a yahoo account synced on the "email" application. Today I needed to access some sent mail from my main g-mail account and for some reason it only showed like 8 of them in my sent box and I needed to view the ones that were missing.

If I go to the "Gmail" app those sent messages are there but not in the "Email" application.

Why is this? I would like to stick to only using the "Email" application instead of having to change between two apps to be replying and checking other messages.

How can I change this?