3.123.172.167
ec2-3-123-172-167.eu-central-1.compute.amazonaws.com
3.127.55.155
ec2-3-127-55-155.eu-central-1.compute.amazonaws.com
3.127.60.70
ec2-3-127-60-70.eu-central-1.compute.amazonaws.com

mx01.hornetsecurity.com.
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mx03.hornetsecurity.com.
mx04.hornetsecurity.com.