Sometimes I miss comments that are for posts a few days old. How do I set it up so that I can receive an email telling me I have a new comment?

In Typepad:

1. Log in to your account.
2. Click on the Weblogs tab.
3. Click on the Configure tab.
4. Click on Feedback.
5. Make sure that Email Notification is checked.

It’s easy for Typepad users to respond to a comment. When you receive the e-mail with the comment, simply click Reply in your e-mail software. Type your reply and hit send.

In Blogger:

1. Log in to your account.
2. Click on the Settings tab.
3. Click on the Comments tab.
4. Scroll down to Comment Notification Address and make sure your e-mail address is in that box.
5. Click on Save Settings.

Responding to comments is not quite as easy in Blogger. When you receive your e-mail notification of a new comment, you cannot simply hit the Reply button and respond (the default e-mail address is ‘no reply’ and it will be lost in the ether). Instead you must click on the commenter’s user id and hope they have an e-mail listed on the profile you’re taken to. If they do not, you can click to their blog or web site and see if they have an e-mail address there. Finally, you can always respond to a commenter in your own comments. This is not a fool-proof way to communicate, though, because you don’t know if they’ll check back or not.

In WordPress:
(These instructions provided by Jordan at Momma Blogga.)

1. Log in to your account.
2. Click on the Options tab.
3. Click on the Discussion tab.
4. Under "E-mail me whenever:," check the box next to "Anyone posts a comment."  (Make sure that the e-mail address listed under Options > General is current and confirmed!)

To respond to a commenter, you can hit reply in the notification e-mail.  However, if you want to have your response shown on your blog, go to your blog and add the response there.