Email has become the most dominant mode of communication these days on the Internet and these days you have your email accounts on the smart phones as well but have you ever stopped to wonder how does email work? You can receive thousands of messages each and every day with the help of the email but how can such an exchange of information take place so rapidly and in such a short frame of time. More importantly, when ever you are using it you do not have to be anything but what is the technology behind the sending and receiving of the email.
What is email?
Email stands for electronic mail. Even though you might be thinking that it is actually very latest but this is the oldest form of communication on the Internet. In terms of the age of the computers, it was a time when computers were very bulky and stored information in limited quantity. If you want to access another computer you had to use a dial-up connection to connect to a terminal on the other computer. The terminal in which the information was stored information of a lot of users. Over a period of time as more and more users realised the for communicating with each other a communication system evolved. The problem in this communication would only send the message to the user whose data was being stored on the same system as yours. The modern-day email system was invented by Ray Tomlinson who also invented the syntax which we use these days to send an email that is @and he was able to send the messages to the user’s which were on other systems as well. This was the starting of the email. The technicals which are involved in sending an email much more complex than simply sending a message with the symbol @.
How does email work?
We can associate the email with the early usage of the text messages on the mobile phones. You might have seen the simple email interface which includes the sender’s address as well as the receivers address and the subject line and the body and this is how the user sees the email interface but underneath that user interface there is a pretty complex technical process which is going on which ensures that your message is delivered to the right receiver within a fraction of the second along with all the information which you are sent including any attachments. The technology which was used in emails has also been advanced these days to allow streaming as well as document transfer.
Let us explain the process of sending an email with an example.
Let us say you are sending the email to email@example.com and this is the address of the receiver. When you click the send button in the email get sent to the simple mail transfer protocol which is also known as the SMTP server. The SMTP server works like the local post office when you’re posting a letter and the job of the SMTP server is to check your address and to check that is where you want to send the email. When the SMTP server is checking the domain to which it is to send the email does not see the domain name but rather it converts the domain name to the hosting IP on which the domain is hosted and in our boy example jayblogs.com would get converted to the IP on which it is hosted and it will look something like this “220.127.116.11” but the SMTP server alone is not able to get the IP of the domain and therefore in order to get the IP of the domain it contacts the domain name system server and the domain name system server works like directory which would have the eyepiece of the domains on which they are posted and it translated the domain into the IP and the next thing which it does is to check out whether on that hosting account there is a mail exchange server which is present or not and if it is presented takes note of the server.
This last process which we explained is same as your local post office contacting the post office and whose jurisdiction the latter is to be delivered and asking from them whether the recipient has a post office box or whether the recipient has at least a mail box. This is done to ensure that the message can be delivered properly.
When all of this info is present with the SMTP server it is able to send the message to the message exchange server. This message exchange server is hosted on the hosting of the domain to which you are sending the email. This server can also be called as the mail transfer agent. This server decides to which exact email ID it is to send the email to. Not that the email has been received by the mail exchange server, the work on the part of your SMTP server or your email client is over. Your friend can now get access to the mail with the help of the POP connection or the IMAP connection.
Ways to access a received email:
As we mentioned above, there are two protocols for accessing the emails and one is the POP protocol and another is the IMAP protocol and both of these are pretty common and in order to access the email you had to use either of them. Below we would be explaining both of these.
POP stands for post office protocol. It is named in such a way because it replicates the way in which you get the mail from the post office. All you need to do is to just connect the server and get all of the mail which you have got and then you can easily disconnect from the server. There is no need for remaining connected to the server all the time. It is a very simple procedure and does not require constant connectivity are a lot of resources as well. The only difference between collecting the mail from the post office and collecting the email with the help of this protocol is that, when you’re using the POP protocol for collecting the mail from the mail exchange server you still leave one copy of all the emails on the server as well. This is the default setting and if you want you can delete them from the server as well.
The problem with the POP, as you might have noticed about, is that the flow of the information is in one direction that is from the mail exchange server to the client. It does not create any problems whenever you are getting messages on one interface. These days you can get the messages on your mobile interface or on your browser interface or on some other type of gadget and therefore when you’re downloading all of these you have to further sort them out to find out where they belong and all this is only possible when you’re keeping a copy of the mail on the server as well and as you can see the process becomes much more complicated as you increase the number of connections which you are having to your email account.
This problem is sorted with the help of the IMAP connection which stands for Internet message access protocol and this allows the information to flow in both the directions. A common example of this is that these days whenever you’re reading a email which is common in your inbox from your mobile phone and the status of the main changes to read from your mobile phone then the same status would be updated in your computer browser as well and therefore you do not have the need to read that email again and you can completely control your email account from any type of device. This is possible due to the bidirectional flow of information using IMAP. This way, you can operate your email account from whichever device you want and the changes would be taking place in all of the connections and whenever you access the email from any connection or any kind of device you would be able to view those changes.
Another advantage of IMAP is that in spite of the bidirectional flow of information you do not need to be constantly connected to the Internet because when you’re off-line and if you’re thinking of making any changes to your email account then when you go online they would be automatically synchronised and the changes would be incorporated as well. As you might have noticed from the working of IMAP it actually works on the cloud principle but since bandwidth and disk space are very affordable you would not have problem with IMAP. Both of these protocols can also be used by a third party client to gather and compile your emails.
SMTP and MTA:
If you noticed your physical mailbox then you can easily realise that you can receive as well as send mail through your physical mailbox. That is not the case whenever you are thinking of sending and receiving the emails because both the different types of servers are used as we explained above, SMTP and MTA. MTA is the server which is used for receiving emails and while any computer can be turned into a MTA server but same is not the case whenever you are speaking about the SMTP server. SMTP server needs a static IP and also most of the Internet service providers block the port number 25 in order to avoid user generated outgoing email to eliminate the chance of spam. The reason that we brought up this point was to make you realise that in case of an email the incoming and outgoing servers are different that is SMTP for the outgoing mails and MTA for the incoming mails.
So, now you would be understanding how complex is the actual working of the email which we just send by a single click of the button.