20:45
So, the email's URL parameters boil down to my email and this string: 2170e9959d30fe730741d42318cef72a8b04d278
without the string, I'm met with the login page (yay!) with it, I am automatically logged in.
note that this URL was sent to me 2 days ago, so I suspect it doesn't expire
just like the site's sessions
Crackstation didn't crack it, so it's not a common string
all in all, a very adventurous unsubscribe click!
I half expect that that string might work for any valid account ...