HI, I'm using Outlook 2011 for Mac version 14.5.4. My Mac OS is 10.10.3.

I am using outlook to sync a gmail address through IMAP. The same email address is synched on my smartphone through IMAP on the Gmail app. 

Over the past week, I've been receiving emails and my outlook would mark it as read, even if I haven't viewed it. I don't view it on either my Gmail app on the phone nor in outlook, but it will be marked as read. 

My mark as read setting is set so that I have to open the email in a new window to be marked as read (something I started doing to try and prevent this problem from happening).

Why could this be happening?