Fastmail offers a masked email feature for one-time email addresses: https://www.fastmail.help/hc/en-us/articles/4406536368911-Ma...
This is a killer feature, I love Fastmail.
Expect this to change, if Apple's anonymous e-mail forwarding becomes popular.
Just like when IT departments (including the one at my company) insisted that everyone use Blackberries because iPhones weren't suitable for a corporate environment.
Once enough C-levels start using any feature, it spreads like wildfire.
They'll continue to block the non-apple ones regardless.