gmail
This is when I click on "All Mail"
And this is when I click on Inbox
Notice that in the "All Mail" pic, the category is "Inbox" for the bunch of recent emails. Whereas in the "Inbox" pic, the last email showing is from Apr 24, and the ones today april 25th (3:52am, 6:55am,….) aren't showing.
If you are testing the POP account by sending emails from your Gmail account, those emails will skip your inbox. It appears that Gmail considers emails to yourself as a special case.
Took me a while to figure this out! Solved when I sent a test email from my old Hotmail account.
I realise that Gmail provides these 4 labels as part of Inbox: social, promotions, updates, forums.
So if a user has not selected to specifically see any of these 4 labels as tabbed category, then all those emails which should lie in that category will show up in Primary label of Inbox. In the below screenshot, as you can see, I have not selected "Updates" category in Gmail.
Example: If a user has chosen not to see "Updates" category, then all emails which should have shown up in that category will show up in Primary category. For this reason, if I query below in Gmail search bar expecting to see everything that is there in my primary category, I won't see all of those emails:
in: inbox -category:{social promotions updates forums} after: 2014/12/11
Best Answer
Your screen shot shows you're looking at the Primary tab. Conversations categorized as Social or Promotions are also in the Inbox, but are displayed on the matching tab.