Create and maintain external cc-list from email communication

A customer needing support is often a member of a larger team, all of who need to be kept informed regarding progress of an issue. This could be supported by:

• Maintaining a record of all email addresses which were on cc when the issue was created by an incoming email (from the known customer contact who has an account)
• Any that already have accounts can be added as watchers, the remaining ones are recorded in the database.
• If subsequent incoming emails on that issue have additional addresses added, the system notices this and adds them to the cc list
• The Service Desk admin can see and edit the cc list to e.g. remove unwanted addresses.

This will work well for the customer, who is then able to use Outlook as their main method of communication with both the internal team and the external subcontractor.

It also avoids unnecessary work adding loads of extra registered users when they really just wanted to be on a cc list, or maintaining email aliases.

I believe I am seeing requests that would be covered by this functionality in both https://jira.atlassian.com/browse/JSD-1593 and https://jira.atlassian.com/browse/JSD-960.

It looks like pretty simple functionality to me, so I hope it can soon be included.