Thanks for your feedback! Sorry to hear that you are having these problems with blocking senders.
Our junk / spam team is looking into this suggestion, and we should have an update in the next month or two.
An error occurred while saving the commentAnonymous commented
Creating rules for this domain doesn't work as the domain name changes with every spam email received. Blocking doesn't work for the same reason. Nothing useful every comes from any email that has appspot in the address, I report all these emails as phishing as that's exactly what they are but nothing gets done. It doesn't take a genius to work out that these are largely coming from the same sender so can you please do something about it.