Seriously. Spotify does not round trip emails.
Well, Insert Expletives Here. Disqus had the nerve to suggest I just roundtrip the password reset and take over the account. And then I can decide whether to nuke it or keep it around as a placeholder. In the Spotify case, I took it over and have requested customer service to get rid of it (partly out of curiosity -- it took a while to convince Dropbox to disconnect the email, and I want to know if it is easier to convince a service to disconnect before or after I've commandeered the account).
None of these accounts (because I caught them early on) have any interesting information attached to them (other emails, phone numbers, physical addresses, etc.). I'm sort of waiting for that to happen.