18.211.219.208
ec2-18-211-219-208.compute-1.amazonaws.com
23.23.9.178
ec2-23-23-9-178.compute-1.amazonaws.com
34.224.244.184
ec2-34-224-244-184.compute-1.amazonaws.com
35.173.153.194
ec2-35-173-153-194.compute-1.amazonaws.com
44.217.95.206
ec2-44-217-95-206.compute-1.amazonaws.com
52.1.164.53
ec2-52-1-164-53.compute-1.amazonaws.com

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