First, I thought that this was Vmware problem.
But now, after testing on several physical machines, I realized certain services didn't return response data when using socat/netcat 1.1 which is supposed to the latest version since last updated.
root@test3:~# netcat 192.168.1.2 25 220 762462a8c4d Microsoft ESMTP MAIL Service, Version: 6.0.2600.5949 ready at Fri, 12 May 2010 18:04:20 +0600 EHLO localhost sdfsafsd ^ root@test3:~#
I've tested it on both windows and linuxes. I found no problem with telnet.