There is a hidden legal danger in not confirming email addresses, and yes, even in the United States. We talk a lot about email deliverability (because hey, we're the original email deliverability company and consultants). And in that context we always explain how using double opt-in (i.e. confirmed opt-in) helps immensely with deliverability by reducing spam complaints and increasing interaction rates. But now we're going to talk about something that people rarely think about: not confirming someone's email address before you use it or add it to a mailing list can have serious legal consequences for you having nothing to do with CAN-SPAM, GDPR, CASL or any email-specific law. It can also have serious consequences for others, consequences that in turn can come back to you in serious, unexpected, but entirely avoidable, legal ways.