I have a side job where I get PR pitches. Far worse, higher frequency, and nastier than any sales emails. Like, emails where the subject line is literally, "Hey {INSERT FIRST NAME HERE}, have you checked this out?"
And then the body says "Hey there, {INSERT FIRST NAME HERE}"
The "Re:" subject is pretty common. Lots of them talk about the weather or ask me how my weekend was even though I have never interacted with them in any way ever. Some of them get very passive-aggressive about you missing out on their pitch, like they're personally offended. One guy recently signed an email "thanks legend". (I was the legend). I usually don't read them, but when I have time they're usually pretty great.