Unlike a postal address, which contains several pieces of information (name, house/apt. number, street, city, state, ZIP code) about where postal mail should be delivered, an email address only provides two pieces of data: the mailbox ID and the domain name.
These are neatly separated by the @ sign with the mailbox ID to the left and the domain name to the right. If your address is username@OnlyMyEmail.com then your mailbox ID is username and the domain name is OnlyMyEmail.com.
