I can only send emails, but can’t receive them on outlook.com…email is coming from a yahoo.com account

Over the past 3 days, I have removed and reinstated a yahoo account from outlook.com.  The emails from the yahoo account were being sent on to me when I initially "fixed" the problem, but as of this morning, I am again without having the yahoo emails sent via pop3 to my email.  Please help as I can't find anyone to call for technical support.