Are you certain that this server even accepts pings in the first place? I am fairly sure we are gathering useless data here. Unless this is actually as bad as it seems, in which case this is positively inexcusable from a company of any appreciable size. Results from 3 different machines:
Local Machine (Denver)
$ ping -c5 sandbox.itunes.apple.com
PING sandbox.itunes-apple.com.akadns.net (17.154.66.159): 56 data bytes
--- sandbox.itunes-apple.com.akadns.net ping statistics ---
5 packets transmitted, 0 packets received, 100.0% packet loss
Production Server (AWS, East)
$ ping -c 5 sandbox.itunes.apple.com
PING sandbox.itunes-apple.com.akadns.net (17.154.66.159) 56(84) bytes of data.
--- sandbox.itunes-apple.com.akadns.net ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 4031ms
Web Server (Linode, Central)
$ ping -c 5 sandbox.itunes.apple.com
PING sandbox.itunes-apple.com.akadns.net (17.154.66.159) 56(84) bytes of data.
--- sandbox.itunes-apple.com.akadns.net ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 4044ms
CLI Web Requests
$ curl -I https://sandbox.itunes.apple.com/
HTTP/1.1 503 Service Unavailable
Content-Length: 62
Connection: close
Cache-Control: no-cache,no-store
Pragma: no-cache
$ curl -I https://sandbox.itunes.apple.com/verifyReceipt
HTTP/1.1 200 Apple WebObjects
cache-control: private
// ... a lot more details i wont bother pasting ...
expires: Mon, 23 Apr 2018 19:27:02 GMT
x-apple-application-instance: 990169
content-length: 16