I'm getting emails titled "Activate account for ...", and addressed to random names of web services at my domain (e.g. reddit@example.org). Also Twitch-related names like pog, kekw and xqc.

Also super annoying are crypto scams sent from an Italian ISP's (tiscali.it, shame on you) email service, even though I tried to contact the ISP, but that's unrelated to this.

Yep, same here, with those exact prefixes...