The structure of email addresd is

accountname @ domain.com

1) Domain name: This part of the email address is the name of server that hosts your emails. It is not necessary that the domain name would always be of a .com kind. It can be anything from the standard list of domain extension (e.g. .org , .net , .gov, .co.in etc.)

A server could that be of a free web-based email service provider (like Gmail, Hotmail, Yahoo! Mail etc.) or server may belong to a specific organization (for example, if you’re working in a company named XYZ … the server name could be xyz.com)

2) Account name (or username): An email hosting server may host emails for one person —or millions of persons.

3) @ Sign: First thing first, in case of email address, this symbol is pronounced as at and not as “at the rate”

This symbol is used in an email address to separate account name from domain name. When a computer tries to understand an email address, it splits the address from @ sign. The part of email address that comes before @ is account name and the part that comes after it is domain name.