My take: someone wanted a technical solution for what is a people/process problem. A hypothetical version of events, just one of many possible scenarios of course: 1) Important communications required by law and/or regulation are sent by email. 2) Contacting customers via email is sometimes unreliable. It is unreliable enough that problems caused by missed emails caused enough pain in some exec's silo that they demanded a solution. 3) "Make sure people read their email" isn't really an actionable demand. The business knows this, so they turned to IT. 4) "Make sure people read their email" isn't really technically feasible either, but at this point it's not about making sure that the customer got the message: it's about making sure that the company is covered if a customer complains about missing communications. 5) To that end, a variety of technical solutions are proposed, and everyone knows that they're all bad or incomplete. The tracking pixel is chosen because it's at the intersection of "least bad" and "lowest effort to implement." 6) Around now, someone probably pointed out the issue with serving the content over http, but changing that requires buy-in from another team. It'll go to their product manager as an inject and maybe get prioritized for next PI (it won't, something more important will come up between now and then). 7) The tracking pixel ships. The team that implemented it stresses that this is an incomplete solution and the business really needs to re-evaluate their processes around customer communications. 8) The email tracking pixel solution gets a bullet point on a slide in a presentation given to managers 3-5 levels higher than the devs who made it. No one mentions that the solution is incomplete and requires additional work and investment. No one ever thinks of it again.