3.210.231.8
ec2-3-210-231-8.compute-1.amazonaws.com
3.82.159.62
ec2-3-82-159-62.compute-1.amazonaws.com
50.19.79.67
ec2-50-19-79-67.compute-1.amazonaws.com

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