[FW1] checking if port 25 is listening on firewall

[NDUKU MUNYARADZI <munyaradzin@FW1-NOSPAMoldmutual.co.zw>]

Title: checking if port 25 is listening on firewall

Hie
Is there a way for me to check from within my network i.e from my Exchange server whether port 25 is listening on the firewall.

May be can I telnet my firewall on port 25 and get an smtp connection is this also possible for my ISP to check if port 25 is listening on my firewall by way of telneting into the firewall on port 25

Thank you in advance

Munyaradzi