An e-mail address has two parts: the user name and a domain name, separated by an @ symbol. The number of domains in a name depends on how many branches are needed to sort it logically. Each address is unique and must be used exactly as given; adding spaces or changing from lower to upper case, or vice versa, may render it useless.
Remarks about the translation
Traduzir em Português,Brasil.
Text corrected. Before: "An e-mail addres has two parts: the user name and a domain name, separated by an @ symbol. The number of domains in a name depends on how many branches are needed to sort it logically. Each addres is unique, and must be used exacity as give: adding space or chenging from lower to uupper case, or vice versa, my render it useless"