The ability to forward tasks with email attachments is crucial. I am researching GTD software for my organization and this is a requirement.

I wonder how people process email/to-do list without this feature. For instance, if I have a proposal sent to me in an email attachment, and I plan to review the proposal next week, I can't do that simply without forwarding the email (with attachment). Otherwise, I have to manually move the file (and still cannot link it to a task).

I like what I see with DoIt.IM, but I would need a strategy for this before moving forward for our organization.