Action Mailbox routes incoming emails to controller-like mailboxes for processing in rails 6. Action mailbox can be used to forward emails to your rails app and process it further as required like storing attachments, creating records from the email body in you db. In this part of a 2 series tutorial we will implement action mailbox with postfix and test in development. If you are only looking to configure postfix in production server to pipe emails, you can read the second part of the tutorial here.