It's interesting that Amazon is portrayed as the "massive corporate server" provider that stores your email "outside your home" on your homepage, yet you use AWS EC2 instances to pipe email traffic to/from Helm.
I understand that it's just an encrypted VPN connection, and are not actually storing email on the EC2 instances. But is there any way for your customers to ensure that? Can your customers shell into the Helm and/or EC2 instance(s)?