To access your emails go to:
https://outlook.office365.com
Type in your SSO followed by @OX.AC.UK
Select 'Next' then login to webauth using your SSO credentails.
Once you have logged in, this should now open up your mailbox and you will be able to see your emails.
Oxford University IT Services' resources https://www.ox.ac.uk/staff/it/getting-started/email