Email tracking pixel support

There once was a font called Smelvetica, a truly terrible prank based on Helvetica. There once was, because Monotype has sent a takedown notice for the git repo. Smelvetica was just like Helvetica except that its kerning was so bad that it was a feature. In fact, it was so bad that the font deserved a takedown notice. It deserved two.

There still exists a mail reader called Outlook, which my sort of people disliked twenty years ago, for good and bad reasons. One of the better reasons was that Outlook would implement harmful features. It still does. For example, it offers tracking pixel support, most often used via one-pixel images but Outlook offers other vectors too, including web fonts.

Bingo.

If you happen to have an old version of Smelvetica, don't like tracking pixels and suffer from a poor sense of humour, you can leverage it to send email that has terrible kerning if and only if the recipient's mail reader supports using web fonts in the way tracking needs. Here's an example of how to do it:

Date: …
From: …
Subject: A little gothic type
Mime-Version: 1.0
Content-Type: text/html

<html>
<link rel="stylesheet"
href="https://fonts.googleapis.com/css?family=UnifrakturCook:700">
<div style="font-family: UnifrakturCook;">
<p>Goth is great.
</div></html>

Since Smelvetica was taken down, I chose to use this font for the example, but the world of web fonts offers many other possibilities. Start looking here. Smelvetica was the best though — the result would look ordinary, yet somehow disturbingly wrong.