As you can read from the link below (Document id: 2003022714315536)
"How to add a firewall rule to Norton Internet Security or Norton Personal Firewall
You need to know how to add a firewall rule to Norton Internet
Security or Norton Personal Firewall.
Norton Internet Security (NIS) and Norton Personal Firewall (NPF)
include three types of firewall rules:
* Application rules. Programs (applications such as email) that
need Internet access to send or receive data use Application rules.
* General rules. Internet protocols and services use General
rules. Programs use Internet protocols (such as TCP) and services
(such as Domain Name Service (DNS)) to access the Internet.
* Trojan horse rules. Trojan horse rules protect your computer
from Trojan horses .............."
You can open the port for specific program using communications tab
from the option page. You can read from the link I give and just
follow the instructions from there (Click on + button beside the
And about if it's risky or not to open specific port. Well it's
depends on the user :)
If you only open the port for eMule, you'll only need to watch what
kind of programs you get from eMule. If it's suspicious, just scan it
first before execute it.
But on the other hand, if you not opening the ports for the eMule, you
can't expect to get high d/l speed because you can only connect to
several servers and not all of the servers which host the file you
Hope this can help.
PS: I don't know if this kind of question violating Google Answer ToS :)
But if it does, please let me know. I'm new on this :)