Best subscribe to post solution?

I’d like to allow my visitors to sign up for updates. I’d need a double opt in and an automated way to send updates as they happen or as a digest per visitors preference. I have messed around with subscribe2 but it doesn’t send out opt in verification emails and I’ve been messing around with MailChimp and it seems a little fragmented.

Let me know what the best solutions that you are aware of. Thanks.