Email service has made it possible to transfer any important message from one place to another at a lightning fast speed. It is possible by a server called’Mail Server’.
When someone sends an email it passes through a number of mail servers which is a complex process. If these series of email servers were not present then we could have been able to send an email to only those recipients whose domain names match with our own.
There are 2 major categories of mail server: 1. Incoming mail server and 2. Outgoing mail server.
- Incoming mail server comes with 2 categories: 1. IMAP and 2. POP3
IMAP abbreviation is Internet Message Access Protocol.
POP3 is an abbreviation of Post Office Protocol version 3.
- The outgoing mail server is the SMTP i.e. Simple Mail Transfer Protocol.
Let’s see how these servers help in sending an email from sender to receiver:
Once you compose the email, click’Send’ button. Then an SMTP server gets connected to your domain of the email client that may be Gmail or Outlook.
This SMTP server communicates with your email address, email address of the recipient, message and if there are any attachments then with the attachment.
This server then checks for a recipients email address. If it finds that the domain names are same then they are routed to the POP3 and IMAP servers and if it finds that both the domain names are different then the senders SMTP server has to make a communication link with the server of the other domain.
At this stage, the SMTP server takes help of DNS server which helps it in finding the recipients server. DNS converts the recipient’s domain name into the IP address as it is required because the senders SMTP server can’t route email without an IP address. Thus it requires both the recipients’ domain name and IP address.
Now the senders’ SMTP server connects to receipients’ SMTP server.
This incoming message is then scanned by the recipients’ SMTP server. If it identifies the senders’ domain name then it simply forwards it to the recipients’ POP3 or IMAP server. From here the message is then sent in send queue and can be received by the receiver once it is downloaded.