inbound-smtp.us-east-1.amazonaws.com.
mx-1.rightbox.com.
mx-2.rightbox.com.
mx-3.rightbox.com.
2600:9000:2043:1600:c:b8a9:f840:93a1
2600:9000:2043:7000:c:b8a9:f840:93a1
2600:9000:2043:7200:c:b8a9:f840:93a1
2600:9000:2043:9c00:c:b8a9:f840:93a1
2600:9000:2043:a000:c:b8a9:f840:93a1
2600:9000:2043:d600:c:b8a9:f840:93a1
2600:9000:2043:dc00:c:b8a9:f840:93a1
2600:9000:2043:f600:c:b8a9:f840:93a1
mxa.mailgun.org.
mxb.mailgun.org.
d2l84tld0aql2x.cloudfront.net.
2600:9000:2043:a400:11:2bd1:ce40:93a1
2600:9000:2043:a200:11:2bd1:ce40:93a1
2600:9000:2043:ce00:11:2bd1:ce40:93a1
2600:9000:2043:3600:11:2bd1:ce40:93a1
2600:9000:2043:fe00:11:2bd1:ce40:93a1
2600:9000:2043:a000:11:2bd1:ce40:93a1
2600:9000:2043:1a00:11:2bd1:ce40:93a1
2600:9000:2043:4a00:11:2bd1:ce40:93a1
d2l84tld0aql2x.cloudfront.net.
2600:9000:2043:fe00:11:2bd1:ce40:93a1
2600:9000:2043:3600:11:2bd1:ce40:93a1
2600:9000:2043:1a00:11:2bd1:ce40:93a1
2600:9000:2043:a200:11:2bd1:ce40:93a1
2600:9000:2043:4a00:11:2bd1:ce40:93a1
2600:9000:2043:a000:11:2bd1:ce40:93a1
2600:9000:2043:a400:11:2bd1:ce40:93a1
2600:9000:2043:ce00:11:2bd1:ce40:93a1
ds4sshub0spi0.cloudfront.net.