You may find following tips useful when setting up continuous integration infrastructure.
Security Use VPN or reverse proxy provider like cloudflare.com to secure your CI infrastructure. Never make your real IPs publicly available, otherwise you increase a risk of being hacked.
Jenkins Use master node and build agents. Master node acts only as web console. Nodes are for compiling and testing.
Notifications If you’re using google apps for domain, you may use Google’s restricted SMTP server to send notifications.