3.228.110.162
ec2-3-228-110-162.compute-1.amazonaws.com
34.197.204.1
ec2-34-197-204-1.compute-1.amazonaws.com
54.147.19.61
ec2-54-147-19-61.compute-1.amazonaws.com
54.243.223.111
ec2-54-243-223-111.compute-1.amazonaws.com

usb-smtp-inbound-1.mimecast.com.
usb-smtp-inbound-2.mimecast.com.