Despite all the advice given here, you *still* don't have the internet connected to port 25 of your SME server. There is a different mail server at altawi.com.au:
-bash-3.00$ telnet altawi.com.sa. 25
Trying 78.46.81.166...
Connected to altawi.com.sa..
Escape character is '^]'.
220-server.tl4s11.com ESMTP Exim 4.86 #2 Tue, 01 Dec 2015 18:08:48 +0100
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
The system which is hosting your website is not running SME server software.
-bash-3.00$ lynx -head -source
http://altawi.com.sa/HTTP/1.1 200 OK
Server: nginx
Date: Tue, 01 Dec 2015 17:14:39 GMT
Content-Type: text/html; charset=utf-8
Connection: close
X-Powered-By: PHP/5.3.29
Expires: Tue, 01 Dec 2015 20:14:39 GMT
Cache-Control: public, max-age=10800
Set-Cookie: PHPSESSID=d4fbe94234986c7af019db390c325b7e; path=/
Last-Modified: Sat, 17 Sep 2011 18:33:29 GMT
Cache-Control: private, no-cache, no-store, proxy-revalidate, no-transform
Pragma: no-cache
You currently don't have any MX records in DNS, which would direct mail to a different IP address than the A record for altawi.com.sa, which is the server hosting your web pages.
As we have told you multiple times, you need to find a mentor who understands basic IP technology, preferable one who understands your native language.