Responding to comments

So, I have a dilemma. Google does not appear to give me email addresses when people leave a comment, so I can't respond. This seems like bad etiquette. (Especially when you consider how many people respond to every single comment, even though their blogs are much busier than mine!) So, I think I have two options. I can either a)leave the comment settings as they are at the risk of being rude, or b) decide to restrict the settings so that people can only comment if they're logged in to Google. I don't like option a because I'd like to be able to respond, and I don't want to be rude. However, I also dislike option b, because I don't think that people should have to have a Google account to be able to leave a message. I know that I don't mind leaving my email address and url on a comment page, but if it tries to force me to log in or sign up for an account I'm not interested. There's always possibility c, which is that I am just missing the setting that lets me respond. If that's the case and you know how to change it, please let me know. Otherwise, I think I'm inclined to leave the settings as-is, and beg your forgiveness if it's rude. Any ideas?