3.210.59.198
ec2-3-210-59-198.compute-1.amazonaws.com
3.225.157.34
ec2-3-225-157-34.compute-1.amazonaws.com
52.87.98.163
ec2-52-87-98-163.compute-1.amazonaws.com

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