Your problem is not the technology of firewalls. Management creates policy
which is enforced by the firewall in order to protect your data from harm.
Petition management regarding your needs for open access and if your
desires rank higher than the need to protect local data, policy will change,
and the firewall will allow what you want.
It is good that your are reading the traffic in this list, because you will gain
an appreciation for the risks, and what some people do to protect against
Good luck. :-)