SIMPLE MAIL TRANSFER PROTOCOL (SMTP)

                        Simple Mail Transfer Protocol (SMTP)

Over the past few months, we have seen an incredible increase in the amount of spam coming to our mail server. We’ve also gotten feedback from you, our customers, about your frustration with the volume of spam you are receiving. You’ve also expressed concern that a great deal of spam contains viruses and exploits (i.e., Trojans, worms, and backdoors) that could allow unscrupulous people to gain access to your computer. This seemingly unending increase in the volume of spam has begun to adversely affect the mail server’s ability to send and deliver your mail effectively and efficiently because much of its resources are being used to process spam.

Based on your requests to “do something” about all of the spam you receive and to help us meet our goal of providing you with exceptional service, we are implementing new measures to combat spam and improve your email services.

Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission across Internet Protocol (IP) networks. While electronic mail servers and other mail transfer agents use SMTP to send and receive mail messages, user-level client mail applications typically only use SMTP for sending messages to a mail server for relaying. For receiving messages, client applications usually use either the Post Office Protocol (POP) or the Internet Message Access Protocol (IMAP) to access their mail box accounts on a mail server. 

introduction

The overall flow for message creation, mail transport and delivery may be illustrated as follows:

Sending MUA → MSA → sending MTA → receiving MTA → MDA → receiving MUA

E-mail is submitted from an message user agent (MUA), the user's email client, to a mail server (MSA), usually using SMTP. From there, the MSA delivers the mail to an MTA, often running on the same machine. These functions may not be distinguished, or merged into one program, and a message may be directly submitted to an MTA: port 587 is used for submission to MSAs (thence to MTAs), while port 25 is used for transferring to MTAs.

The MTA looks up the destination mail exchanger records in the DNS, and relays the mail to the server on record via TCP port 25 and SMTP. Once the receiving MTA accepts the incoming message, it is delivered via a mail delivery agent (MDA) to a server which is designated for local mail delivery.

The MDA either delivers the mail directly to storage, or forwards it over a network using either SMTP or the Local Mail Transfer Protocol (LMTP), a derivative of ESMTP designed for this purpose. Once delivered to the local mail server, the mail is stored for batch retrieval by authenticated mail clients (MUAs).

Mail is retrieved by end-user applications, the email clients, using IMAP, a protocol that both facilitates access to mail and manages stored mail, or the Post Office Protocol (POP) which typically uses the traditional box mail file format. Webmail clients may use either method, but the retrieval protocol is often not a formal standard. Some local mail servers and MUAs are capable of either push or pull mail retrieval

Features:

Our email server runs several email filters which are being deployed as the first line of defense for your email service. These filters are detailed below:

Blacklists

A Blacklist is a database of known Internet addresses (or IP’s) used by persons or companies sending spam. These lists use various methods to identify spammers. Open relays are used mainly by spammers to obscure where the mail is originating. Worse, they can deliver a single email to an open relay and address it to hundreds of recipients, thereby causing the open relay to do most of their work. With this blacklist in place, the mail server will reject mail coming from open relays. Such email will be rejected with a message to the sender.

Attachment Type Blocking

For your safety in using email and to help prevent the spread of viruses and other exploits, we also block the following attachment types: exe, com, scr, vxd, pif, vbe, vbs, vex, cpl, XL, bat, cmd. These are all known to be used by viruses. If you need to receive an attachment with a file which uses these blocked extensions, we recommend that you ask the sender to zip the file before sending it. The sender may also change the file extension which you can then rename upon receipt. If you choose this option, make sure the sender provides you with the correct file extension so you can rename the file properly.

Virus Scanning

We scan all incoming and outgoing email which traverses our mail server for viruses using virus scanning engine.

SYSTEM   STUDY

Existing system

When you send out your mailing without SMTP server, it has some major drawbacks:

• It involves more operations and therefore takes more time for each message to be sent
• It involves communication with multiple servers, with varying response times (some may be very “far”), therefore again it takes more time
• Speed may be limited
• The server may not accept more than a given number of messages per hour / per day and refuse extra messages
• No multiple connections may be allowed
• Too strict ant spam automatic filters may be enforced, leading to legitimate messages being refused

proposed system

SMTP Server is powerful but extremely easy-to-use SMTP server software, which can send mails from local host to the recipients' mailboxes directly at an amazingly high speed. Arrived or not, you will get feedback instantly.

Short for Simple Mail Transfer Protocol, a protocol for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an e-mail client using either POP or IMAP.

ADVANTAGES:

Ø  Effective e-mail Communication

Ø  Be clear and concise with message

·         Don’t be a novelist

·         One page / 10-sentence email

·         Attach word documents for longer communications

Before sending

• Reread message
• Check grammar, words left out and misused words

-          Words witch our spilled write butt knot used inn the write weigh - this sentence runs through the spell checker perfectly

• Use spell check

Addressing an email

• ‘To’ - directly addressing
• ‘Cc’ - indirectly addressing
• ‘Bcc’ - blind copy unknown to the rest

Use specific subject line descriptions

• Accurately describe the content

Attachments

• Title appropriately
• Size
• cards

In addition, SMTP is generally used to send messages from a mail client to a mail server. This is why you need to specify both the POP or IMAP server and the SMTP server when you configure your e-mail application. This project is one which can be used in web/window application like C#, ASP.NET, VB, SMTP component allows your applications or web pages to create and send email messages over SMTP protocol just in a few lines of code.

User can send messages as plain text or in the HTML format.
SMTP Component can send email to any email address with or without SMTP server as parameter. Email can contain any number of attachments, unlimited recipients, CC's and BCC's. Send Email directly from you web page via applications/browsers.

System CONFIGURATION

HARDWARE CONFIGURATION:

                        Processor                        :   Pentium 4

            Processor Speed            :   2.40GHz

            RAM                             :   512 MB

            Hard Disk                      :  80GB

            CD Drive                       :  Samsung 52X

 SoftwAre CONFIGURATION:

                         Environment                           :   Visual studio .NET 2005

            .NET Framework          :    VERSION 2.0

            Language                      :   ASP.NET with C#

            Operating System         :   WINDOWS 2000/XP

            Back End                      :   SQL SERVER 2000