This tutorial is going to show you how to set up Postfix SMTP relay with Mailjet on Debian. Postfix is a popular open-source SMTP server. Previously I wrote an article how to quickly set up your own email server on Debian with Modoboa, which helped a lot of readers run their own email server.
However, some readers told me that port 25 is blocked by hosting provider or ISP as a way to control email spam, so they couldn’t send email. Vultr may not may not blocks port 25 on your server, but they would unblock it if you ask them to, so I recommend Vultr as your hosting provider. Some other hosting providers or ISPs like DigitalOcean would not unblock port 25, so what can you do to bypass this blocking, if you can’t or don’t want to change your hosting provider?
SMTP Relay To The Rescue
Read full tutorial here: https://www.linuxbabe.com/debian/configure-postfix-smtp-relay-mailjet
