3. Email Concepts
When someone sends an email, then as well as the message itself, they include the recipient's email address. The mail transmission system uses the address to route the message to the recipient's mail server - this is just a computer system equipped for storing and providing access to email. The mail server holds the message until the recipient connects to it to check for new mail.
The main central email server at Oxford is called Nexus. Nexus is one of the systems run by OUCS (Oxford University Computing Services). The next section Central Email tells you about the central (as opposed to a Department or College) mail account.