I put a significant amount of work into preventing this “jump” from happening, and here it is, cutting off a full half of a Substack.

We need to do a better job explaining that this is a problem.

The thing causing the jump, as far as I can tell? Too many styled links. Because the CSS is inlined it means that every link has to carry that color code.

This is less than 3,000 words and “jumps” halfway in. I regularly hit the 3,000 word mark and don’t “jump.”

Another factor behind this email jumping may be the length of the links. A single link I randomly pulled from this newsletter is 444 (!) characters. That means Casey is using up half a kilobyte by just placing a link in his newsletter—in a medium where kilobytes matter.

By comparison, a Tedium link, which uses Amazon SES to handle URL redirects and such, takes up 288 characters. It’s not consistent every time out of course but on average I likely will be able to put more links in my newsletter.

I guess here’s what I worry about. Substack and platforms like it are great because it makes running an email newsletter easy to do for mere mortals. But there are technical underpinnings to sending an email that it would help for regular users to understand.

I mean, who is going to tell the writer that the reason their message didn’t show up in full in the Gmail window was because Substack generates longer links than an alternative offering might?

I’m checking a few other newsletters to understand the impact of this. It does appear to be affected by the length of the link. But here’s an example link I recently spotted. Somehow Substack blows up a 59-character URL to more than 400 characters.

But a URL that’s roughly twice as long doesn’t seem like it adds much more to the length of the obfuscated version.

Talking about this on Newsletter Nerds, it appears to be a Mailgun problem, based on the URL structure.