Anyone using a forwarding/alias service might also want to search the web for "disposable" email domain blacklists, and petition the maintainers to remove the service you use from their lists.
These lists are often adopted by web developers, leading to many web sites rejecting forwarding addresses, or sometimes even accepting the addresses and then silently dropping messages while claiming to have sent them. As these lists become more common and widely used, forwarding services are becoming useless on more and more sites.