Presumably if I don't want to receive spam emails I'm also unlikely to allow a website to send me notifications. I'm unlikely as well to install an extension for a very specific service I'm not going to use very often. Extensions are a privacy concern and consume memory needlessly.

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.