Skip to main content

What is SMTP ?

 SMTP 
-SMTP stands for simple mail transfer   protocol.
-SMTP is an application layer protocol.
-The transfer protocol of SMTP is TCP(Transmission control protocol)    because TCP is a reliable and connection Oriented protocol.TCP gurantees e-mail delivery .
-It uses TCP port 25.
-A few webmail services like G-mail use   unofficial port 465 for SMTP.
-SMTP requires each message in 7-bit   ASCII(American Standard Code for   Information Interchange ) format.


-SMTP is used by the client to send mail to servers because SMTP is a push protocol.It is used to send mail from sender to senders mail server and it is also used to send mail to receivers mail server from senders mail server .
- Recepient download the mail from the mail server using POP3 or, IMAP .They can also just view the mail on the server by using webmail.
Some SMTP commands: 
•HELO and EHLO:-Command that initiate a new protocol session  between client and Server.The EHLO command request them to respond with any optional SMTP extension it support.
•MAIL FROM:- Identify sender.
•RCPT To:- To identify intended recipient .
•DATA:-send actual data.
•QUIT:-Terminates the conversation with   the server.


Comments

Post a Comment

Popular posts from this blog

What is FTP ?

  FTP -FTP stands for file transfer protocol. -The Transport protocol of FTP is TCP     because it requires reliability. -The port number of FTP is 20/21.Port 20   performs the task of forwarding and   transferring of data and port 21 performs   the task of transmitting of commands. -It is a standard internet protocol provided   by TCP/IP for transmitting the file(which     may contain any kind of digital   information,such as text document,   movie ,image etc.) from one device to   another. -It is mainly used for transferring the web   page files from their creater to the   computer that acts as a server for other   computer on internet and it is also used   for downloading the files to computer   from other servers. -The main competitor for FTP is Http and   now sites runs Http servers instead of   FT...
1 comment
Read more

What is Hub ?

what is a Hub ? Hub is a networking device which is used to connect multiple devices together in LAN(local area network). Hub works under physical layer of OSI(open system interconnection) model. It is purely hardware device where data reaches from one or, more nodes and is forwarded to one or, more nodes. Traffic is high in hub because it is purely hardware .It has not software to determine the destination address.so,it does only forwarding but not filtering.Lets take an example for better understand:-             If pc1 sends data to pc2,Data will goes to pc2 and also data goes to pc3 and pc4.which means hub can not do filtering .It can do only forwarding.                                                                                  ...
1 comment
Read more