Plurrrr

Since I wrote How to write really slow Rust code and its sequence, Part 2, I have received so much feedback and suggestions to make my Rust code run faster that I decided I had enough material to write another post, this time focusing on more advanced tools and techniques available to Rust developers rather than on how to avoid noobie mistakes that will totally destroy your Rust code performance, as the previous blog posts did.

If you use email with your own domain, a lot of the burden of authenticity has suddenly shifted from your service provider to you. This guide will hopefully give you the information and practices you need to keep your domain's email authentic and less vulnerable to spoofing.

We'll cover the three major components of modern email domain security: DKIM for signing, SPF for sender verification, and DMARC for stricter enforcement of the other two. It is assumed the reader has a basic understanding of DNS and has experience using email with their own domain.

Recently, I encountered a problem. My domain didn't correctly implement SPF, DKIM, or DMARC.

Then, I encountered a second problem: I had no idea what those were, and seemingly nobody has written about SPF, DKIM, or DMARC in a way that a human can understand, not to mention implement. Every article I found was either highly technical, trying to game SEO to sell me something, or too high level to be useful.

As a result, I've had to do a lot of hard work and research to understand this problem. Hopefully, because I had to do this, you won't.

There's two main sections here: a human explanation of what these things are, followed by a reasonably straightforward way to implement them.

Let's say you have more than one version of Python installed on your machine. What version does python3 point to? If you said, "the newest version", you may actually be wrong. That's because python3 points at the last version of Python you installed, not necessarily the newest; python3 typically gets overwritten every time you install some version of Python.

This is a bit annoying when you simply want to work with the newest version of Python (e.g., creating a new virtual environment). It would be convenient if there was a command which just always used the newest version of Python that's installed ...