Hello.
And welcome everyone. So in this video we are
going to see what are some ports and protocols which
are related and associated with emails.
So the first protocol that we are going to see is SMTP.
Which works on port number 25?
The full form of SMTP is simple mail
transfer protocol.
SMTP is generally used for sending the
emails.
The next protocol is POP3.
POP3 works on port number 110
the full form of POP3 is post office protocol.
And POP3 is used for receiving
the emails.
The next is imap4.
it works on port number 143
the full form of IMAP is internet message access
protocol.
This is the newer version of POP3 as you
can see.
This is also used for receiving emails.
So we have seen.
For sending we use SMTP for receiving we
use POP3 or imap4.
So, let's see how our email works.
As you can see on the left hand side. This is Bob and
on the right hand side. It is marry.
So let's say Bob want to send a message to Mary.
Hi, let's meet for a coffee.
So Bob type some message after composing the
message he sends on send now that
email.
Is send through the SMTP server
as we saw that SMTP is used for sending now
the message is transferred.
To the email server of the Bob's ISP
ISP stands for Internet service provider Whoever
has provided the service to
Bob.
After this the ISP does a DNS lookup
of the recipient email. So
what is DNS lookup DNS lookup stands for
domain name?
system lookup in which it checks if the recipient
email is right or wrong if
it is wrong you will get
Email bounce back onto your inbox saying
that recipient does not exist.
Perfect. So after this check is done. The email
is further transferred using SMTP. And
now the email is received by
the Mary's ISP, which is providing the
internet service to marry.
So how they are going to receive it. They are going to receive it
using POP3 or IMAP as we already
discussed that POP3 and IMAP is
a receiving protocol. So they will
receive the message and give it further to Mary's inbox
this way Bob and
Mary can successfully communicate using an
email.
I hope you guys understood. Thank you.