34.242.56.177
ec2-34-242-56-177.eu-west-1.compute.amazonaws.com
54.72.71.254
ec2-54-72-71-254.eu-west-1.compute.amazonaws.com
54.77.148.253
ec2-54-77-148-253.eu-west-1.compute.amazonaws.com

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