Email is something we use everyday but how many of you would be able to explain what really happens from the moment you click “send” to the moment the recipient opens the message?
The moment you hit the send button, the email is sent to an email server by using the Simple Messaging Transfer Protocol (SMTP).
At the same time, at the DNS level, the email’s domain is translated into an IP address.
For a few nano seconds, the message hops around the Internet as it makes the connection to the destination computer.
After going through the Firewall / Proxy, the message delivery agent (MDA) then delivers the message to the server’s mailbox.
In parallel, the DNS-based blackhole list filters though messages and blocks email spamming.
At the destination computer, a POP/IMAP server fetches the message and stores it in the computer’s mailbox, ready to be read.