I'm sorry, I didn't understand your question. Can you please explain in a bit more details what you did, what you expected to happen and what actually happened?
I simply want to forward an email message to AC to be attached to a specific ticket as a new comment.
In order to do this I need to add the ticket ID-tag to the subject of this email. (As described by gcortesi above)
My problem now is finding out the exact ID-Tag from tickets.
Hack Guy proposed is just that - a hack, not feature that we promote or support, so we did not try to make it easy :)
Real ticket ID can be found in general URL-s, suck is Complete for example. That you'll see ticket's global ID, not it's project ID. That value should be used in emails if you plan to use this hack.
I'm sorry, I didn't understand your question. Can you please explain in a bit more details what you did, what you expected to happen and what actually happened?