It seems there is a simple answer.
The only piece of action required is that anyone who uses blogger and who would like comments returned/replied to needs to edit their profile. I have not suddenly acquired the ability to fathom these computery things BUT SarahandJack have!
If you would like to activate this bit of blogger then log in, go to 'edit profile' and there is a little tick box (it won't have a tick in it) that says ... show email?Tick It.
PLEASE ;-)Then your profile will look like this (with a nice blue link to your email address) ::
Mine does now because I've just ticked my box.......
Doing this means that you can reply to comments via your email...aren't computers clever!!