3.208.163.51
ec2-3-208-163-51.compute-1.amazonaws.com
3.213.148.152
ec2-3-213-148-152.compute-1.amazonaws.com
3.222.184.44
ec2-3-222-184-44.compute-1.amazonaws.com
34.201.96.195
ec2-34-201-96-195.compute-1.amazonaws.com
35.169.108.217
ec2-35-169-108-217.compute-1.amazonaws.com
52.71.193.229
ec2-52-71-193-229.compute-1.amazonaws.com

inbound-smtp.us-east-1.amazonaws.com.
mxa.mailgun.org.
mxb.mailgun.org.