"Bad signature" error when key server is not available.

[yukinying]

When the key server is not available and one got an email which is signed with a key that the extension has never seen, it would report "BAD signature". It makes me feel like there is an active attack going on. However, it is not.

So, would it be making more sense to report "key server not available" in this case?

Here is the screenshot of the error: