Useful SMTP Command

The following article will outline some basic SMTP command which you can use in order to :

- Test SMTP server working or not
- Test Open relay of a SMTP Server

Here are the steps & command you can use:

• Open command prompt if you are using windows or using Linux terminal and type the following command:

$ Telnet <SMTP SERVER> 25

where <SMTP SERVER> is the host IP Address or Hostname of your SMTP server, for example your SMTP host name is SMTP.4bing.com, then you might want to type: 

$ Telnet  smtp.4bing.com 25 

• You'll receive greeting from the server as below from the server, which means a session has already been established

220 smtp.4bing.com Microsoft ESMTP MAIL Service, Version: 7.0.6001.1800 0 ready at  Tue, 30 Jun 2015 15:12:50 +0700

• Continue with the following command  

1. Type HELO <your mail server domain>, and then press ENTER.
2.  Type MAIL FROM:<sender@domain.com>, and then press ENTER.  
3. Type RCPT TO:<recipient@remotedomain.com>,and then press ENTER. 
4. Type Data , then continue with Subject: <Your Email Subject> and then press ENTER
5. After step 4 above you can now type anything as mailbody
6. when finish with your mailbody type "."  and then press Enter 
7. Type Quit to end the session and email should be sent out if everything works perfectly

•  see below example

Difference Between Linux & Unix

There are  many similarity between Unix and Linux , and in fact, Linux was originally created to be similar to Unix. Both have similar tools for interfacing with the systems, programming tools, filesystem layouts, and other key components.

 However, Unix is not free. Over the years, a number of different operating systems have been created that attempted to be “unix-like” or “unix-compatible,” but Linux has been the most successful, far surpassing its predecessors in popularity.

You may have heard of Unix, which is an operating system developed in the 1970s at Bell Labs by Ken Thompson, Dennis Ritchie, and others.

What is Linux

What is Linux?

It's a freely distributable, operating system which can be installed on PC, laptops, notebook, tablet devices, mobile, video game, server, hardware appliances, and more.

The official mascot of the Linux kernel is a penguin character named Tux. This Linux logo was suggested by Linus Torvalds in 1996. The name Tux is derived from (T)orvalds (U)ni(X).

It has various distributions, those are well known operating system such as Debian, Ubuntu, Fedora, Redhat, SUSE, The Linux Is frequently packaged as Linux distribution for desktop/server use, and including in the package is the Linux kernel (the Operating system core) as well as supporting tools & libraries.