How To Install and Configure Postfix as a Send-Only SMTP Server

[Postfix](http://www.postfix.org/) is a popular open-source [Mail Transfer Agent](https://en.wikipedia.org/wiki/Message_transfer_agent) (MTA) that can be used to route and deliver email on a Linux system. If you manage a cloud server with applications that need to send email notifications, running a local send-only SMTP (Simple Mail Transfer Protocol) server is a good alternative to using a third-party email service or running a full-blown SMTP server. In this tutorial, you will install and configure Postfix to send emails by local applications only. Choose your operating system to get started.