itunesconnect using application loader behind a firewall

I had the same problem.

The Application Loader Guide shows the range of IP addresses and ports that need opening.

After following the document I was able to successfully submit a binary for approval.

https://help.apple.com/itc/transporteruserguide/#/apdATD1E112-D1E1A1303-D1E112A1126

Go to Preferences, Advanced, select DAV only.

This will use port 443 (aka HTTPS) for uploading.

There is no way the company will open those ports for me ;p