Primary & Other boxes keep showing RED

there were 2 email addresses and I cancelled the lower address on the right hand screen.
Since this I now get 2 RED boxes along the top toolbar Primary and Other.
They disappear when I check the unread email box?
How do I stop this please.

That is the number of recent messages that have been received since the last time you were in that tab.

The option to disable it is in Menu > Settings > Mail > Categories.