33.11 Summary
A complete, end-to-end email system consists of a Mail User Agent (MUA), Mail Transfer Agent (MTA), Mail Delivery Agent (MDA) and the SMTP protocol. Ubuntu provides a number of options in terms of MTA solutions, one of the more popular being Postfix. This chapter has outlined how to install, configure and test postfix on an Ubuntu system both to act as a mail server and to send and receive email using a third party SMTP relay server.