As CERN user you have also an email address at CERN. You can access, setup, etc. your email account on the webpage: https://mmm.cern.ch/
You can login to this page with your nice account.
In case you want that all mail sent to your CERN mail address is sent to your e.g. BU account you can set up forwarding all emails to your other email account on this page as well.
PS: I have added the link to the MMM service to our link list as well.