Many people work with RT exclusively via email. During an email thread attached to a ticket, they might CC someone on a response because they want them to see what's being discussed, answer a question, etc. The new person will see that email, but if they aren't added as a Watcher of some sort on the RT ticket, they'll miss other correspondence.
We've released a new extension we've found handy in detecting when this happens so you can add people to a ticket to keep them in the loop. RT::Extension::NonWatcherRecipients, despite the big name, is a simple extension that detects extra email addresses and notifies you about them. The typical recipients are the AdminCcs on the ticket, since they can go into RT and update the Watchers, so it installs a new template called "NonWatcherRecipients Admin Correspondence". You can select this as a replacement for the standard "Admin Correspondence" template and see this sort of message when extra emails are found:
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From: "A User" <a-user@example.com>
The following people received a copy of this email but are not on the ticket.
You may want to add them before replying:
https://YourRT.com/Ticket/ModifyPeople.html?id=12345
Cc: "Non Watcher" <non-watcher@example.com>
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The link takes you to the People page for that ticket so you can easily add the new people.
If you have customized templates you can drop in the following:
{ RT::Extension::NonWatcherRecipients->FindRecipients(
Transaction => $Transaction, Ticket => $Ticket ) }
Bug reports or comments are welcome at bug-RT-Extension-NonWatcherRecipients@rt.cpan.org, pull requests via github.