SMTP - Simple Mail Transfer protocol
It is a text based protocol . Here we can specify one or more recipients of a message along with the message and encoded objects .
Message -------------------> remote server.
Then the communication between the client and the server takes place.
SMTP uses port 25
POP - POST OFFICE PROTOCOL
POP is a very simple protocol that only allows downloading of messages from your Inbox to your local computer. Generally, once transferred, the email is then on your local computer.
we normally use POP3
.POP3 uses port 110.
IMAP - Internet Message Access Protocol
It is a much more advanced protocol that allows you to see all your folders to quickly view subjects and message bodies of emails. But on downloading a larger email it delays its speed. IMAP also allows you to synchronise mail folders on the web, so that you see the same folders and messages wherever and however you access your email.
IMAP uses port 143.
Like gmail drive that saves your pictures and files . So that yu can access and download whenever you want
@ppk ::::REPLY TO THE QUESTION
Why above protocols use different ports?is there any significance in that ? Also i assume that SMTP is used in gmail ,SMTP is text based protocol.what do that denote "text based"? So i cannot send other things than text like images ?
The above protocols uses different port Since, For networks, a port means an endpoint to a logical connection. The port number identifies what type of port it is. So we have dedicated port number for each of this
If it is SMTP : Then we use port number 25 for SENDING EMAILS.
It is the standard protocol for sending emails across the Internet.
And SMTP is used to send only text email . Since there were a problem with binary files like IMAGES , standards such as
MIME came into picture (Multipurpose Internet Mail Extensions ) were developed to allow binary files to be encoded and sent via SMTP.
If it is for POP3 ::: Then we use port number 110 which is a dedicated port to receive emails from a remote server to a local email client. The main disadvantage of POP3 is when you use POP3 to connect to your email account, messages are downloaded locally and removed from the servers.
If it is IMAP :::: Then we use port number 143 for retrieving emails .
Here you may have the doubt that both POP3 and IMAP are used for the same purpose. Yup exactly it is .
While the POP3 protocol assumes that your email is being accessed only from one application, IMAP allows simultaneous access by multiple clients. This is why IMAP is more suitable for you if you're going to access your email from different locations or if your messages are managed by multiple users.