My IT-teacher has a website. Aside from it looking like from 1980 (which is ok), he has a "security js Mail decryption":
In his page there is a <script> with a simple yet custom de/encrypt function. Then his E-Mail is an <a href="javascript:mailto:function('rubberish173848'>private email</a>. (Or something like that)

You can just run this link (open email app and read it) or use the same function and same href in the browser console and read it. It sounds so stupid.

(Yet I figured out he probably doesn't want bots to spam his mail, so maybe I am stupid)