Simple Mail Transfer Protocol (SMTP). Team: Zealous Presented By: Vishal Parikh (003749955) Ribhu Pathria(004698318)
Vishal Parikh (003749955)
Jainip Desai (004677635)
SMTP stands for Simple Mail Transfer Protocol.
Mail is a Text File.
Mail Header: It defines the sender, the receiver, the subject of the
message and other information
Mail Body: It contains the actual information in the message
Why to use an envelope if sender and recipient’s email address is
already contained in the headers of the message itself?
SMTP clients and servers have two main
It prepares a message and encloses in an envelope.
It transfers the mail across the internet.
HELO : Request to initiate SMTP session
MAIL FROM : Sender’s E-Mail address
RCPT TO : Receiver’s E-Mail address
DATA : Body of message
QUIT : Terminates SMTP connection
RSET : Aborts mail transaction
VRFY : Asks receiver to verify the validity of the mailbox
EXPN : Asks receiver to identify mailing list
HELP : Causes receiver to send help information
NOOP : Forces server to verify the communication with SMTP
1. Transaction Initiation and Sender Identification
S: HELO sjsu.edu
R: 250 Hello sjsu.eduS: MAIL FROM:<email@example.com>R: 250 Ok
2. Recipient Identification
S: RCPT TO:<firstname.lastname@example.org>R: 250 Ok
3. Mail Transfer
S: DATAR: 354 End data with <CR><LF>.<CR><LF>S: <The message data>
S:.R: 250 Ok, message accepted for delivery: queued as 12345S: QUITR: 221 Bye
The Server responds with a three digit code that may be followed by
the text info.
SMTP is one of the most widely used and implemented application. With the explosively growing reliance on electronic mail for commercial and personal services, there grows the demand of authentication and confidentiality. To complement the weak security feature of SMTP industry use PGP-SMIME-PEM. Still there is need of implementing the measures to eliminate spam and other security breaches.