The other useful guide I’ve been following for setting up email lately has been Secure Postifx Using Let’s Encrypt.
Let’s Encrypt is a pretty cool certification authority that makes setting up HTTPS for websites not just a doddle, but also free. I’ve been very impressed with it. But it can also be used to provide certificates for other non-web services too, like SMTP, POP3, and IMAP, as per the guide above.
