Are you accessing Gmail from your computer?
May i connect with you remotely to troubleshoot the issue directly? Thanks
Which application are you using on your computer to access gmail and how?
Are you able to access via www.gmail.com ?
Go to Settings -> Filters and see if there are any filters there?
On the gmail.com website, after you've logged in there is a settings wheel on the top right, click on it and choose settings.
are you under the tab "Filters & Blocked Addresses"