depois de instalar o nmap, ao colocar o comando nmap -sT -p 25 ondisc.pt aparece-me este texto:
starting Nmap 6.00 (
http://nmap.org ) at 2014-07-14 11:58 west
Warning: File ./nmap-services exists, but Nmap is using /usr/local/bin/ ../share/nmap/nmap-services for security and consistency reasons. set NMAPDIR=. to give priority to files in your local directory (may affect the other data files too).
Nmap scan report for ondisc.pt (80.172.253.111)
Host is up (0.039s latency) .
rDNS record for 80.172.253.111: limamx.dot2web.com
PORT STATE SERVICE
25/tcp open smtp
Nmap done: 1 IP address (1 host up) scanned in 1.02 seconds