Regardless of exactly how it happened, it appears I’m not alone and it is related to the Pine64 store. They need to button some things up on their end.

same here. i emailed pine64 about it but had no response so far

Yeah.. That is definitely possible too.. But.. If it was a day after, its probably less likely.

A lot of websites also use systems like Postmark for outbound emails.. so, it could also be one of those companies harvesting the data

Just to add in the technical realm. It could also be a security vuln, a very common one through which the attackers get massive amounts of emails and that'd be shared with tens of thousands of other websites. Like, auto-harvesting through a vuln.

In any case no selling or leaking, that would just not work.

Who would bother buying random email lists from companies (unless you clicked something when signing up)? Email lists aren't worth anything

More likely a browser extension or your email host providing them