Emails Moving from Inbox to Trash

Emails Moving from Inbox to Trash

Hi. I have an issue that popped up recently. I started missing emails on my POP clients. I logged onto the web client and found that all of my new emails, as well as all of my old emails somehow moved to the trash folder.  New emails are continuing to get moved into the trash folder. 

Any idea why this would happen? Also, is there any way to move the emails in my trash folder back into my inbox? I tried on my own, but it only lets me do 200 at a time (and I have >11,000).

Thanks so much for any help that you can offer.

BB