The central Oxford University email is part of the Nexus365 service, which also gives you access to an online calendar. You can give other people access to your calendar, and schedule meetings, share contacts, tasks, files and folders with your colleagues. You can also use the other features that come with Nexus365: OneDrive for Business, Skype for Business, Teams & Groups, Delve, Office 2016 download.
You can access your Nexus365 email in different ways: online in your web browser, in an email program ('client') or on mobile devices. The IT Services web pages offer a wealth of information about how to set up and use the different email tools.