shell:$ nslookup -timeout=2 -retry=1 '50-courier2.push.apple.com'
Server:		1.1.1.1
Address:	1.1.1.1#53

Non-authoritative answer:
50-courier2.push.apple.com	canonical name = 50.courier2-push-apple.com.akadns.net.
50.courier2-push-apple.com.akadns.net	canonical name = us-north-courier-vs.push-apple.com.akadns.net.
Name:	us-north-courier-vs.push-apple.com.akadns.net
Address: 17.57.144.244
Name:	us-north-courier-vs.push-apple.com.akadns.net
Address: 17.57.144.246
Name:	us-north-courier-vs.push-apple.com.akadns.net
Address: 17.57.144.247
Name:	us-north-courier-vs.push-apple.com.akadns.net
Address: 17.57.144.245
Name:	us-north-courier-vs.push-apple.com.akadns.net
Address: 2620:149:a44::7
Name:	us-north-courier-vs.push-apple.com.akadns.net
Address: 2620:149:a44::6
Name:	us-north-courier-vs.push-apple.com.akadns.net
Address: 2620:149:a44::4
Name:	us-north-courier-vs.push-apple.com.akadns.net
Address: 2620:149:a44::5