Nice list, thanks for putting it together & sharing. Slightly OT, for people with email sending experience: I've noticed that some of these lists require you t

Nice list, thanks for putting it together & sharing. Slightly OT, for people with email sending experience: I've noticed that some of these lists require you to confirm an email subscription ("double opt-in"), which afaik is standard operating practice for any email list these days. Yet a couple (Bootstrappist, Web Design Weekly to name a couple at random) don't, they just send a welcome email. Are those two able to avoid the double opt-in requirement by virtue of being larger/older/more established lists, or are they assuming their open rates will keep their deliverability % high, w/o needing the extra confirmation step? Has the double opt-in requirement become a relic?