how to fix counter on mail says 5 only 2, just example?

If you asking what I think you are, there is nothing wrong.

If the email program says you have 5, but you only see two in your inbox, it's because the other 3 have been identified as spam and transferred to the junk mail folder.

That's why you should check the junk before deleting it, sometimes the spam checker makes mistakes.

If this wasn't the problem, please restate or elaborate on the question.