At first, I did have pb. So I would disable the firewall, send the message and re-enable the firewall.
Then, I think "well... I'm supposed to be working with computers, so, let's have a look at the settings ...." (after a few months of using it !).
And sure enough, a simple set up, allowing this web site to do what I deny to most sites and it was OK.
Now I understand why my boss has upgraded my salary for so long .... <img src="/images/graemlins/grin.gif" alt="" />