18.208.235.1
ec2-18-208-235-1.compute-1.amazonaws.com
3.208.91.7
ec2-3-208-91-7.compute-1.amazonaws.com
34.234.110.84
ec2-34-234-110-84.compute-1.amazonaws.com

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