What is an E-mail Address?
An e-mail address is a text code such as [email protected] or [email protected] that identifies the source or destination of an e-mail message sent by an e-mail provider.
All e-mail addresses have an @, which is pronounced "at." For example, [email protected] would be pronounced "john at gmail dot com."
The part after the @ is a domain name, which is case-insensitive. When an e-mail is sent, the e-mail provider uses the domain name to query a DNS (domain name server) for information about how to send e-mail to that domain name. Not every domain name receives e-mail. If you own a domain name, you don't get e-mail by default, you must set it up first. By convention, many websites accept e-mail through contact@ (e.g. [email protected]), but this, too, doesn't always work.
The part before the @ is the username, which is case-sensitive (at least technically). When an e-mail is sent, the sender sends the message to the e-mail server (provider) cited in the domain name information, but what happens after that depends on the server.