Why does gmail keep moving emails to trash?

Recently gmail has started moving emails from certain senders to the trash (not spam) automatically. Senders include Groupon and LivingSocial but also a wildlife newsletter, amazon and some other newsletters. I only access my gmail from Chrome (maybe once a month) and the Mailbox app (by Dropbox) on my iPhone. I have no filters or additional folders set up. How do I make it stop?

Don't worry about that call on this tollfree no. 800-652-1462 and iim sure you will get the resolution… I had this problem but now its working great!