I have a problem with my newly purchased YubiKey: I always get an "Authentication failed" on the test site.
Unfortunately I cannot contact support either. I get the following mailer daemon mail:
Quote:
Delivery to the following recipient failed permanently:
     support@yubico.comTechnical details of permanent failure: 
Message rejected by Google Groups. Please visit 
http://mail.google.com/support/bin/answ ... wer=188131 to review our Bulk Email Senders Guidelines.
Same when I tried to reply to 
order@yubico.com