emails are disappearing

I just put this email program on my computer a few hours ago.  My emails have been appearing in it.  I just went in to check my new emails, and alllllll the other emails from earlier that were in my inbox are gone.  Literally.  I am wondering where they went to?  Is there something in setup that I missed? 

Thanks for any help.  

Hello Lori,

Is it possible that the missing emails are in any subfolder or in Local folders? The only automatic removal works for Trash folder, where emails can be deleted after closing the program but not for regular Inbox folders. When you check the emails on your webmail, are you also missing them there? And please let me know what email account it is.