error: GPG validation failed! The update downloaded successfully, but the GPG signature verification failed channel: GPG validation failed, channel f

# /usr/bin/sa-update
error: GPG validation failed!
The update downloaded successfully, but the GPG signature verification
failed.
channel: GPG validation failed, channel failed

I got this error while trying to update a system with the spam date bug.

==
https://issues.apache.org/SpamAssassin/show_bug.cgi?id=6269
==

fix was fairly simply, just update the GPG key.

http://wiki.apache.org/spamassassin/SaUpdateKeyNotCrossCertified
==
Running this should fix it:

    wget http://spamassassin.apache.org/updates/GPG.KEY
   sa-update --import GPG.KEY
==

Once this is done, you should be able to update for the date bug

==
/usr/bin/sa-update
service spamassassin restart
==

Done.!