Microsof Outlook

I updated my computer from windows 7 to windows 10 on the internet.  after that I was only able to receive emails on my Microsoft Outlook mail.  Sending test mail fro Microsoft outlook was also ok, but receiving from others ....no chance.  All mail settings and passwords are correct.  Can there be anything in Northon which stops Microsoft Outlook from sending mails.  Need help urgently.  brgds