 netstat -a
Here it is ....
[root@mailserver1 ~]# netstat -a | grep 25
tcp 0 0 localhost.localdomain:10025 *:* LISTEN
tcp 0 0 dataserver1:42068 dataserver1:7025 TIME_WAIT
tcp 0 0 *:7025 *:* LISTEN
tcp 0 0 localhost:39125 localhost:54076 TIME_WAIT
unix 3 [ ] STREAM CONNECTED 8104825 |