Have you checked that your Outlook is correctly configured ? Swisscom has informed since Spring time that unprotected accesses to the e-mail servers will in the interest of users gradually non longer be accepted.
I have done this, but Outlook is still not receiving my emails I keep getting this message the server for account "Bluewin" returned the error "5.7.0 ...authentication rejected." Your username/password or security settings may be incorrect. Would you like to try re-entering your password?