As Paris Geek wrote, "redirect" (aka "bounce" in some mail older clients, such as pine/alpine, elm...) is not available in Aquamail (unfortunately).
As far as I know, this suggestion was made a few times in these forums. (Possibly more in Russian then in English, at least recently.)
I don't believe I've commented on this before.
So, @Kostya: I also would support request for this useful feature.
One of the use cases is when you want to resent the message to someone without modifying it at all, thus (1) avoiding messing up the complicated HTML formatting and (2) allowing the ultimate recipient to print it with "From" from the original sender, not you.
This is very convenient when redirecting various e-tickets, reservation and purchase confirmations (from airlines, online stores, theaters, ..) that often have very sensitive HTML formatting to your family members, associates, etc., so that they can print them.
I see a potential concern that sometimes such messages could have a higher probability to be tagged as spam ("From" field doesn't correspond to the sender, intermediate "Received" headers, etc.). But sometimes this can also happen when people do automated forwarding from one account to another one (e.g. via .forward in Unix, or via "virtual hosting", "forwarding addresses", and "aliases" inside organizations. The latter is e.g. user@domain.com that you can configure pointing to user@department.domain.com or anti-spam, switchable limited-time aliases such as user-13rand35@domain.com that point to the "private", unexposed address such as userName@domain.com.)
As an aside, @Paris Geek: "anonymous" forwarding is very different. It does not really anonymize you (the person forwarding), but rather removes the original sender from the "From" line (as well "To" line(s)) in the forwarded message. So, it anonymizes the content of the original message.