Smtp Service - How To Eliminate The Basic Problems

By Author: luis henry
Total Articles: 9
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SMTP is the most popular protocol for mail transferring and extensively used throughout the world. While sending email messages through the SMTP service, the net users may encounter a variety of problems. This article is focused on resolving the SMTP communication problems in case of only Microsoft Exchange-based servers.


As it has been previously stated that the problems may be of various types, therefore, the steps of troubleshooting also vary a lot depending upon the nature of the problem. You may experience problem while sending messages over the SMTP service between the two Microsoft Exchanger 2000 servers. In such a case, the very first thing you have to do is to check the connectivity. Such test can be done by using a Telnet on the sending server to build up connection to the destination server's port 25. Generally the SMTP service uses port 25. If you face a problem in mails receiving, check the connectivity from the host, residing on the net but not in your network, to an SMTP server.


There are several and significant variations of SMTP service as far as the Microsoft product line ...
... is concerned. In case of Microsoft Windows, SMTP is packaged with Internet Information Services or IIS whereas the SMTP service was fitted in the option pack in Microsoft Windows NT server 4.0. The modern versions are expectedly improved where the IIS is an integral part of the operating system. Addition or deletion of the IIS program is much easy in the recently released Windows versions. You have to just click on the add/ remove button in the control panel. Both the Exchange 2000 and Microsoft Exchange Server 2003 have an access to the additional features while using the SMTP from IIS. The latest versions 4.0, 5.0 and 5.5 of Microsoft Exchange Server use their own SMTP versions in the form of either the Internet Mail Connector or Internet Mail Service.


It is a noteworthy point for the net users that they should make sure whether the SMTP starts on the same server that provides the SMTP service. Getting the 220 response from the remote server signals that the SMTP has kicked off on the right server. SMTP, being a text-based protocol allows the mail sender and receiver communicate with each other through the strings of command and requisite data supply over the Transfer Control Protocol connection. An SMTP session comprises of a series of commands issued by a client and the corresponding responses made by the SMTP mail server. A session may have zero or multiple transactions. The transaction has three sequences namely Mail command, RCPT command and Data for text message sending.


The Mail command specifies the return address whereas the RCPT command decides regarding the message recipient. The DATA command is used to send the body of the message. It comprises of a group of commands to which the server responds two times. The first response is a signal that the SMTP mail server is ready to receive the text and the second response is made after the end-of-data. The reply of each server may be either positive or negative. Negative replies may be of permanent nature such as reject, a permanent failure by the SMTP mail server. A drop exemplifies a positive response in the event of message discard.