34.211.10.190
ec2-34-211-10-190.us-west-2.compute.amazonaws.com
35.83.60.65
ec2-35-83-60-65.us-west-2.compute.amazonaws.com
44.241.174.240
ec2-44-241-174-240.us-west-2.compute.amazonaws.com

inbound-smtp.us-west-2.amazonaws.com.
mxa.mailgun.org.
mxb.mailgun.org.