Peter, sadly this does not help with the following szenario: A company has a central email incoming folder for mails from customers. From there the email should be forwarded to a project in Project Manager to be stored there for reference with the project. As this is not a "reply to", you send a new message to the project. And you don't want the secretary to remember cryptic keys which she has to compute manually to send the mail, but use "p-$project_id@myserver" to send the mail to.
So I agree, if we have a "reply to", then we could circumwent this issue and also have additional security for e.g. forum postings, but this is not a general solution for the incoming e-mail challenge.
