You should be able to set the firewall to allow the source, not the popus, as presumably each has a different url address, which would also need added to any popup blocker you run through your browser or anti-virus. The firewall is interested in the route the message takes not the actual url of it once you receive it. I would try contacting the technical support for your job and asking them if they can specify how to set up your firewall instead of turning it off.