Simple Mail Transfer Protocol Computer Science Essay

fair Mail get rid of communications protocol Computer Science EssayElectronic mail as known as telecommunicate is a function of institutionaliseing and received sum over the internet. Basically, protocol is a standard method use by sender or recipient to guide in breedation. It can also be explain by to deal with email, sender or recipient must access to mail server by a mail lymph gland to exchange information by using variety of protocol such(prenominal) as SMTP, pappa and mummer.1.2 Simple Mail Transfer protocol (SMTP)SMTP is only use to send email, but not received email. SMTP provides a set of ordinance that allow server to break up the email core to different parts of categories that can pick up by the server and Its a kind of simplify the communication between server and email. For users, they can see the port of their email softw are when writing an email message, but once the message has been send out on the internet, everything is change into string of text that can understand by the server. This string of text is separated by numbers and code words that apply to identify the purpose of each section and SMTP provides these codes to let email server understand what they means.SMTP also can set up communication rules between the servers. For example, server can identify themselves and will announce what communication they are trying to perform and the some other server will authorize and identify the operation, if something went wrong, the receiving server may reply an error message.The greater advantages of SMTP are simplicity and trustworthy. SMTP provides the simplest form of sending an email address between various computer and network. Users only need to enter recipients email address and type in email message to send and the email will go through a simple process from the SMTP to exchange server for the recipients computer. Since the SMTP is simple, email message can be direct quickly and easily. In addition, SMTP is trustworthy bec ause when the outgoing message is not successfully sent, SMTP will keep trying to re-send the same email message until its successful.Since SMTP was created in the premature of 1980s. SMTP was build according to basic concept of server communication, because of that SMTP consists of several disadvantages. In those days, Internet was only use by very close community that by and large trusted each other, that cause SMTP has lax security holes. For example, it is easy to send email message with fake sender address. This also cause many email-based viruses dissemination over the internet. Although there have been improve has been made, but it can still cause problems.Most servers these days actually use an updated version of SMTP called Extended Simple Mail Transfer Protocol (ESMTP) that allow to sends pictures or music file through their email program.1.3 Post Office Protocol (POP)Post Office Protocol (POP) is used to retrieve email from a central base where the email stored and des igned to support offline email processing. When the email is delivered to the server, a remote email client will periodically download the messages from the server and filter them into appropriate users folder. Once the email has been received from the client, the message will be permanently deleted from the email server. cardinal of the advantages of POP is once the email message is sent to the client, the message can be read immediately whether user is connected to the internet or not. Furthermore, POP is a very popular email protocol that all email clients can support it.There is a disadvantage of POP is inadequate for the industrious user. Because of email message is downloaded to recipient PC, the user will only able to access the message from one PC. According to this, POP may cause hazel and inconvenient for user to read message only from one PC.Diagram 1 POP email system1.4 Multipurpose Internet Mail Extensions (MIME)MIME allows user to transfer image, sound, and program a s non-text email format attachment in email across the internet. MIME was introduced to improve SMTP in order to send message other than ASCII characters through web client and web server. Now, MIME provides the following extension to email Non-text attachment such as video, images, audios and other multimedia messages. Send multiple objects within a single message. Write header information in non-ASCII character sets. Write text with unlimited length. Character sets other than US-ACSII.Nowadays, almost every mail is transmitted using MIME format through SMTP. Content type that defined by MIME also benefits Hypertext Transfer Protocol (HTTP) and other communication protocol in email transmission function. As MIME can support character sets other than 7-bit ASCII, languages based on other alphabets can be display correctly presented in a basic email. In turn, SMTP that only support 7-bit ASCII has the limit of languages display that only adapted for writing in English and other smal l number of language. Moreover, MIME allows user to send other type of information such as images, sounds videos and software program program which was not possible to do so in earlier time. In additional, to identify the true nature of a file that is being used in transmission, MIME provides header information to client who received the transmission and selects the protocol to transmit data according to the header. Furthermore, to ensure non-text attachments will be transferred successfully with maximum protection, MIME used Base64 encoding to encode the non-text information into text when email transfer. Overall, these all explain the advantages of MIME bring to email user nowadays. non surprisingly, there have been a numbers or disadvantage of MIME. For example, the encoding process of MIME may somehow increase the complexity of gateways because a 7-bit cosmea has to encode 8-bit message. Furthermore, a multipart message could lead to passing same data to decode several time. N evertheless, it now has to pass only the lower-level parts to encode earlier than whole message to reduce troublesome.2.0 How to apply the SMTP and MIME with ASP.NET2.1 Requirements to use SMTP and MIMEThe following is the requirements to develop ASP.NET applications.The .NET Framework 2.0A code-authoring environmentA web server, such as Internet Information Services (IIS), and permission to write files to web server.To send email using SMTP server, fsocketopen function need to be enabled. Furthermore, Outgoing art to port 25 by default or whichever port that use to connect to SMTP server must be allowed. Lastly, there must be a valid SMTP server to send email. If one of the above is not successful, errors message such as No connection, Unauthorized and Timed Out will be displayed.REQUIREMENT OF MIME2.2 Steps on how to create apply and configure SMTP and MIME in ASP.NET project.2.2.1 SMTPOpen up the default.aspx code window from the project, and examine the code used to send an em ail.Include three imports in default.aspx to run the project and send email message.The application uses the System.Net.Mail libraries to format and send STMP based email message. bear the variables used to contain information used in sending email.Code send buttons Click event handler, this handler capture users inputs from the page and assign to associate variables, then format the message using the variable content. Server and port setting are extracted from the AppSettings contain in web.config file.