[rcxdude]

All your suggestions are orders of magnitude more effort than 'click a button to get email notifications if someone comments on the issue'. That's what people are complaining about, not that it can't be in principle done if you duct tape enough things together yourself.

[db48x]

I disagree. Sending someone a quick email is not an order of magnitude harder; both are the work of seconds, maybe minutes if you have to find the right email or bug report first. But if you think that it is, maybe you should offer that service. Give people a website where they can click on a button on any email in the mailing list to subscribe to replies as if they had been CC’d in the email itself.