Sending and receiving emails is something that is done in such a mundane manner that we never stop to think how this automatic, quick mail communication takes place. The key element in email communication is the email server. There is a very interesting technology behind the functionality of the email server.
Basically, email communication is made possible by SMTP and POP3 or IMAP server types Email1and1 . The most widely used mail-client software is Microsoft Outlook or Mozilla Thunderbird, and Mac OS X’s Mail. All these email software packages perform the same function, which is downloading incoming email into the machine from the mail server of the concerned email account like Yahoo, Gmail or AOL.
Communication that occurs on the internet is through the client-server connectivity. In simple terms, the client is the computer connects through a unique internet protocol address through the internet and the server is another computer connected to the internet which takes care of hosting and serving web pages.
Whenever an email is sent out, the system connects to your email service’s mail server which is a centralized computer that manages a specific service. For instance an email server handles emails. This email server which is responsible of sending email is called Simple Mail Transfer Protocol (SMTP) server. The SMTP server passes the mail to another SMTP server to the destination through several hops. Every email has the sender’s and recipient’s address.
Each domain refers to a unique web address known as Internet Protocol (IP) address. The link between domain names to their IP address is stored in the Domain Name Registry. The SMTP server contacts the DNS server where the registry is stored. The address is sent back to SMTP server by the DNS server.