Cert on https://www.mulberry.com / PGP key?

Hi,

The cert on https://www.mulberrymail.com appears to be a self signed cert 
now? Just had a friend contact me after re-installing their PC and pointing 
it out.

Is it self signed for a reason (i.e. other than cost?)

Also - on the download page there's PGP signature files, but I can't find 
the Mulberry PGP key to use with them anywhere on the site? - Is it still 
around?

Just trying to verify the authenticity of the downloads on the site before 
my friend re-installs 4.0.8 for Windows....

Thanks,

-Karl