My advice is not to listen to the no doubt tiny percentage of people complaining about the email delivery. Hard fact of business: if people hate commerce, they won't buy from you. It's a mistake to tailor your business around people you can't sell to… probably sounds obvious, but we're all built to respond to the squeaky wheel instead of the 4 other wheels who roll along happily.
Don't hamstring your future business success simply because your offer isn't right for everyone with an "add comment" button!
Email newsletters -- opt in, permission marketing, like yours -- are gold. Readers love them, and they do gangbusters for your sales!