Can I configure my mail client (or Gmail's web app) to send mail from a plussed address?

If I had the email address example@gmail.com, I could use a plus sign to generate a virtually unlimited number of alias names that I could use on each service I signed up on. Like example+TwitterSpam@gmail.com -- If I received junk mail with a To: header that included TwitterSpam, I'd know exactly where the sender got my email address.

My question is, if I receive email from one of these plussed addresses and want to reply to it, the reply will contain a From: header with my true, un-plussed address: example@gmail.com. Is there any way to configure either my mail client or Gmail's web app to reply from the same address that the message was delivered to, plus sign and all?

Why? The immediate case that comes to mind is one where I sign up for Xyz Company using example+XyzSpam@gmail.com and then later open a customer service support ticket. Some of these systems send emails to example+XyzSpam@gmail.com that ask me to reply directly to the email with Idea to update the ticket. I don't want to (at best) "reveal" the bare email or (at worst) appear to be a different person that the ticketing system won't be able to track.