In this article, I will show you how to set up Postfix as a send-only SMTP server on Ubuntu 18.04, 16.04, 19.04. I will first show you how to do it for a single domain, then you can apply the steps for multiple domains if you need to.

Use Case
You have a website/web application that needs to send transactional emails to users (such as password-reset email). Most likely, there’s no need for users to reply to these emails, or if they reply, the reply emails will be sent to your dedicated mail server. In this case, you can set up a send-only SMTP server on the web server using Postfix, which is a popular SMTP server software.

#mail server #linux #opendkim #postfix #ubuntu #ubuntu server