I believe if you install XP today, it will still receive all the updates that were available up to April of 2014, MS just stopped supplying new updates after that date.
Based on the System Requirements listed here: Link RemovedI believe a Virtual Machine running XP should be able to handle Autodesk 2006. Email and file transfer is not an issue.
This does depend somewhat upon the machine you plan to run VirtualBox on though. The machine you install VirtualBox on must have enough cpu power and memory to support running it's original OS as well as the Virtual Machine. If your machine, referred to as the "host" machine has a marginal cpu or is short on RAM, it may not be suitable. If your machine has less than 3GB of RAM, it...