*Paubox Email API & SMTP Solutions - General

• Paubox Email API & SMTP Solutions: Comparison

*REST API

• REST API v1
• REST API - SDKs

*SMTP Server Solution

• Implement a basic Ruby on Rails application that sends mail using the Paubox SMTP Server
• SMTP Server Solution - API Code Samples

*SMTP Relay Service

• SMTP Relay Service - Ports to Use