I had a problem, i could not get emails from one of my friend which is in the same network with the others (I got mail succesfully) and me.
I also asked admins of my network but they couldn't find anything about that.
Then, I understood that; i had got emails, but i couldn't see them
Because; i had created a new folder a rule for my friend and then i had deleted the folder and sent it to DeletedItems Folder. But Outlook went on sending emails to this folder. 
For your information..