.My comments all use a "noreply" email address, instead of my actual email address. How do I have people email their replies to my comments?This appears to be one more way which Blogger is trying to safeguard our Blogger accounts and blogs, from malicious, technically astute blog thieves.
Some time ago, we observed that this precaution appeared to be unique to Blogger accounts which used Google and Google+ profiles - and did not involve Blogger profiles.
It appears that this is now universal, and includes Blogger profiles, as well as Google / Google+ profiles. It's likely that the noreply email addresses are being offered to keep more blog readers from, inadvertently, exposing their email addresses to email mining techniques.
In remembering the long ago discovered "nice blog" spam, it's possible that "nice blog" spam was originally developed to help the spammers gather email addresses, using very innovative technique.
All that a spammer has to do is to post a "nice blog" comment, select "Email follow-up comments to me" - then watch as the Inbox fills up with follow up comments from bloggers, willingly giving up their email addresses to every stranger also selecting "Email follow-up comments to me", in that comment thread.
The people willingly providing their email addresses, to the world in general, are perfect targets for hackers later trying to brute force access to the Blogger accounts, starting from the provided email addresses. Use of the "no-reply" email address prevents this type of mischief - and reduces the workload of Google Security, as they would otherwise have to verify account / blog integrity, for hacked accounts and blogs.
For even more protection (which is not a bad idea, in any case), consider using Google 2-Step Verification, to protect your Blogger / Google account from hacking.