Email Filtering With Sieve

Sieve, defined in RFC 5228 , is a programming language constructed for the express purpose of filtering email messages. And, on a Sieve-enabled server, it can do a lot of work.

Shortening My URLs With tekdmn.me

Has anyone noticed that I’ve been giving out URLs of the form tekdmn.me and not teknikaldomain.me? Well, not only did I buy another domain that’s just a shorter version of this one, but it’s also, at the moment, the singular domain I have that’s 100% serverless. How? Cloudflare, obviously.

MTA-STS Is a Thing... Well Then (also feat. TLSRPT)

If you’re just curious, MTA-STS relates to SMTP, in the same way that HSTS relates to HTTP. Except, naturally, it relies on, you get three guesses… yes, DNS. And this is what it is, and how to set it up.

Publishing SSH Fingerprints in DNS

So here’s the thing about SSH: The first time you connect to a server, you have no real idea of if that’s legitimate or not, right? Well, you could compare the key fingerprint to the fingerprint that the server admin gave you and make sure they match, but nobody does that.

Well… there is a way. Using everyone’s favorite always-broken service, DNS.

Delta Chat: Instant Messaging Using... Email?

So this is a fun one, and likely a long one. Come, let’s talk about the unlikely backing for a decentralized, privacy-focused communications platform, the very weird ways in which IMAP can be used, and a hopefully final wrap-up to my streak of rambling about PGP.

PGP Key Discovery Mechanisms Explained

Okay, final thing on PGP after talking about PGP itself and Signature and trust levels, we have… How you can get someone else’s public key.

There’s a few common ways to do this:

• Keyservers
• Web Key Directory
• DNS
  • CERT record
  • PKA TXT record
  • DANE OPENPGPKEY record

Let’s discuss how they all work.

PGP Trust Levels and Signature Types Explained

So last time we introduced the basics of how PGP works. This time, we cover something slightly more in-depth: signature types, and trust levels.

PGP (GPG) Explained

Pretty Good Privacy, or as it’s more commonly known as by its most popular client’s name, GNU Privacy Guard, is a method of encrypting and/or signing your messages using the power of public key cryptography. And, while it can get extremely complex, the basics of using PGP are, actually, pretty simple. So in the words of the great Angus Deveson, Let’s get started.

Using Cloudflare's HTTP/2 Server Push

For those unaware, when using Cloudflare to proxy your site, HTTP/2 support is usually on by default, and highly recommended, and you can also enable HTTP/3 too. But, for a while I thought that Cloudflare’s HTTP/2 would rob you of one of the really cool and touted features of HTTP/2: the server push. Well, as it turns out, that’s completely possible. Let’s dive in.

Comparing IMAP and POP

For those of you that have ever tried to setup email on your phone that’s more than just GMail, you’ve likely been asked how you want to access the account, either POP or IMAP, and were likely told the difference is that “IMAP keeps messages on the server.” Well, let’s go over the specific differences here, to actually give a more complete understanding of what each protocol is like.