This document discusses setting up a mail server infrastructure using Amazon Web Services. It involves using Postfix on EC2 instances behind an ELB for SMTP ports 25 and 465. Route53 is used to route mail to the ELB using a CNAME record. Messages are then sent to SES using the SendRawEmail API after converting the encoding to CP932 in a Lambda function. Various tips are provided around configuration of Postfix, relaying to SES, and addressing encoding and capacity issues.