title: How to find a specific cron job?
body: <p>My question is how to find a specific cron job?</p>
  
  <p>I have a cron job that runs daily on my web/email server and I'm sure it exists, because I get an email every day about it. It's a LetsEncrypt SSL certificate renewal. Now I want to modify it, but I can't find it anywhere.</p>
  
  <p>(Edit: moved "things I've tried" from here into the answer)</p>