If I'm willing to give a fake registration email I probably don't care about privacy and this is just for throwaway anyway. I'm not going to give any personal info to a website I don't trust with my email in the first place.
I also don't understand how this is not going to be blacklisted like any other anti-spam email service.
Maybe I'm not the target for this product bu this seems to bring nothing new in a slightly more annoying way.
This is somewhat tangential to your points, but I see this type of comment a lot. Chrome extensions are just renamed zip files that contain all the JS, HTML, and CSS for their extensions. It is easy to take a look at the source code if you have any privacy doubts. The author might try to obfuscate the JS, but it should be trivial to see if there are outgoing connections being made. Google also makes it simple to disable extensions with a couple clicks if you want to keep particular extensions disabled except when you are actively using them.
> Extensions are a privacy concern and consume memory needlessly.
Yes, that's why we don't ask for any permission, so the extension only gets activated when you click on the button.
> I'm not going to give any personal info to a website I don't trust with my email in the first place
Everyone can get hacked, governments, big companies... so who do you trust enough to give your email?
> I also don't understand how this is not going to be blacklisted like any other anti-spam email service.
Some services might block our addresses some day, but that would be a mistake because nBox is not a disposable email service.