changes in email delvery

Hello,

My electricity went out yesterday, so I had to download everything back onto my computer, including my email accounts.  After finally accomplishing that, I find that ALL my email messages have to be opened via a tab,   (like an attachment)  and this is not normal for this computer, and a pain due to having to open every single email as an attachment. 

Can someone please direct me as to getting my emails via a normal delivery method. 

Thanks!