System to send and receive messages and e-mail via a communications network between the computer and other equipment central character. Mail (“”mail”” in English) in this so called from being realized by means of electronic mechanisms like. Including the message exchange function refers to the broad exchange messages by means of electronic systems and services, software, provided by mobile phone SMS, various Internet services and apps in between. Here represents the generally refers to the message exchange system was narrow with a variety of protocols, such as SMTP, POP3, IMAP4 and MIME Internet standard for (communications protocols) and data formats, in modern times simply speaking of e-mail. e-mail sender and recipient are used instead of the full name and address and the email address (the email address) called a unified format string. This is expressed in the form of the account name @ domain name, account name becomes a personal part in the distinguished name represents the distinguished name of the managed portion of the domain name user membership and subscription by your organization’s network. Get a computer for personal use, and receive a computer on the network connected to the Internet, known as the mail server (mail server) is installed, or send mail to external network request from the user, reminding visitors sent from the external mail. Be a point of contact for users and other servers, such as postal service on the postal system role playing. Temporarily to the email received and available storage space on the mail server in each user corresponds to the p.o. box (mail box). Contact mail communication via e-mail users to interact locally (mail client, mailer), received an email in your mailbox, to present to the user. Businesses, government agencies and universities, such as running a mail server and email address published by the members, Internet service provider (ISP) and mobile phone operators as part of the Internet access service subscribers email address published by. In addition, portal sites such as anyone freely to get email address free of charge, available free (free email) service is also widely popular. You can e-mail only (text) data include in principle. Mail only with great character messages are written without the use of a special notation and format that text email. Embedded, such as formatting or decoration and layout using HTML Web pages is HTML mail. Also, files using this embedded in e-mail, MIME (Multipurpose Internet Mail Extension) is provided as a standard method is not a text format, such as audio, video and data files, program files (binary data) into text data in fixed steps, send text message with that attachment (file attachment). e-mail Web (WWW) along with the main services of the Internet widespread and functioning as a social infrastructure to communicate the message in the information communication. Implemented as a Web application can be used from a variety of devices, such as PCs, mobile phones and smart phones, tablet computers, on display in the Web browser, to operate Web mail (webmail) system is also commonly used. application systems, such as a broadcast transmitter to send 1 e-mail to multiple recipients simultaneously on the e-mail system and simultaneous delivery easy to group common address for the communication among members and to discuss mailing list (mailing list), or the Publisher to subscribers on a regular basis by email to reach “”newsletter”” (mail magazine) in active use. ‘Phishing’ attempt to dupe recipients to exploit on the other hand, advertising mail to send to multiple email addresses indiscriminately addressed to “”spam”” (spam mail) and an attachment mechanism of computer virus infection viral email (virus mail), source, attempt to steal your confidential information (phishing) and exploiting the e-mail abuse and crime, and has become a social problem.