Thanks for posting this! Always good to warn people.
I'm curious, are you actually a Let's Encrypt user? Looking at the blurring you are. And was the e-mail send to an e-mail address you've used for Let's Encrypt usage perhaps?
@lestaff Any idea what this is? And how it can be possible that LE users are being spammed? Or is it perhaps due to a data leak at Shopify?