### Tek's Domain

#<NTA:NnT:SSrgS:H6.6-198:W200-90.72:CBWg>

# 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.

# 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 (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.

# Comparing IMAP and POP

So here’s a fun one. Have you ever noticed that even for huge changes to a repository, a git push only sends over a few kilobytes, maybe a few megabytes at most? If you’re familiar with the internals of git, you know that git stores an entire copy of the new file on commit. So how are these changes so small?