Oooh I think this is great

Another one, as an example, check the FDA food and drug alerts for medicine you take. I guess the pharmacy should email you but who knows, it's just filtering an xml for a set of regex. I built a cheap example myself on a micro self hosted server I use for other things

Having quick and easy email behind a very simple url is great. Another usecase I use is I have a tiny http endpoint which just emails based on the url parameter (e.g. since it's only me my.server.com/email?msg=DONE_AI_training). Then I can use it to notify me when a long running job is done, using curl or the easy off the shelf requests that's in any language