shell:$ nslookup -timeout=2 -retry=1 'smart-com-kh.mail.protection.outlook.com'
Server:		1.1.1.1
Address:	1.1.1.1#53

Non-authoritative answer:
Name:	smart-com-kh.mail.protection.outlook.com
Address: 52.101.157.80
Name:	smart-com-kh.mail.protection.outlook.com
Address: 52.101.124.117
Name:	smart-com-kh.mail.protection.outlook.com
Address: 52.101.137.0
Name:	smart-com-kh.mail.protection.outlook.com
Address: 2a01:111:f403:cc1a::8
Name:	smart-com-kh.mail.protection.outlook.com
Address: 2a01:111:f403:cc1f::4
Name:	smart-com-kh.mail.protection.outlook.com
Address: 2a01:111:f403:cc09::