Peer, in your email analogy, the email client wouldn't stop working but it would immediately stop receiving anything from that particular sender (who is known to send spam/malware) and not receive any more from that sender until you re-enabled it. That's the equivalent of what SkyDemon is doing.

You appear to think it is "normal" for an aviation device to send out erroneous data. It is not. I cannot emphasize that enough. We do have experience of working with many different pieces of hardware, remember.

It is very likely that other navigation apps simply are not performing the checking that we do. We are rigorous, because being incorrect is unthinkable to us. Obviously, the vendor of your device which is outputting erroneous data is not checking that output either. It's extremely sad in the world of aviation that either of these cases are true.

My one concession would be that we would be willing to talk with the vendor of your problematic hardware and if they have a known bug where ONE particular erroneous piece of information is regularly sent by one of their products, and that piece of information was deemed by us to be harmless, we would alter our code to ignore that particular field.