E-mail is the process through which the world communicates today. It is the fastest mode of text message, over long distances. Hardly ever do we doubt about how things that matter to us, work. Have you ever amazed how email servers work?
Email is less probable to collapse, but it absolutely helps in having a big picture of how message reaches across the world in a blink of an eye.
Communication that takes place on the internet is due to the client-server connectivity. In simple words, the client is the system connected with a unique IP address through the internet and the server is another system connected to the internet which manages hosting and serving of web pages. Email servers are nothing but software programs that run on high speed machines. These high speed machines are deliberated in the manner that they hold the requests of millions of clients. All the requests are fulfilled at the same time to those who access an e-mail.
These servers work only with listed e-mail clients. If a specific server receives an e-mail from one of the registered clients, then it carries out the following functions.
1. Analyze the registered clients
Initially after an email is received the server examines whether it is from one of the registered e-mail clients on the basis of which it also takes an incoming email or refuses it. An email is obtained by a server through port 25 if it is an SMTP protocol or through port 110 if it is a POP3 protocol.
2. Divide the username and the website name
This server then divides the username and the website name. And, if the website name and the mail site to which it will get delivered are the same then it is sent to a POP3 or IMAP server for the remaining procedure to be performed.
3. Ask domain name server for IP address
If the receiver e-mail address is different from the sent email id then the server will make contact with the domain name server or the DNS and ask for the IP address of the mail client to which your mail is to be delivered.
4. Gather emails in a database
E-mails are then accumulated in a database or list on the server before it is sent to the recipient email address.
5. Resend and produce appropriate error messages
If the SMTP protocol server cannot find the IP address of the receiver mail server, then the mail is lined up and periodically sent for a definite number of times before a message sending failed message is produced stating the causes for its failure.
These are the essentials of the working of email servers. However, a variety of servers may have some small changes, but the necessary working remains the same. The main work of an e-mail server is to obtain a message from the registered or listed clients and then send it to any receiver address. Thus, the working of an e-mail system is relatively simple in principle.