Adding to/cc to request participants after issue creation

[Kimi Nakashima]

Is it possible to add any email address listed in to/cc as a request participant after the issue is created. We have everything set up to add CCs as request participants when an issue is created, but what if a CC or To is added to a reply after the issue is created.

For example, say you have Customer A and B who both work for Test Organization. Customer A emails the helpdesk for a thing and creates TEST-100. Our agent replies back to Customer A to request more information about the thing. Customer A replies to the email but adds Customer B to the To field and asks Customer B for more information about the thing. Customer B replies with more information about the thing, but because he's not listed as a request participant creates a new issue, TEST-101. The issue key is listed in the email subject but because the initial email did not have Customer B as a recipient he creates a new issue.

Is there any way to stop this from happening?