When will this take effect? I downloaded a few puzzle cache GPXs and I'm still seeing "Mystery" in the GPX files.
Can you check and see what web server you are on (http://www.geocaching.com/whoami)? I was informed that some of the web servers had to be manually restarted in order for the change to take.
On WEB05 Build: Tucson.Main.release-20140616.Release_129 about 4 minutes ago, I still got a "Mystery". Based on the build date, I expect at least that server hasn't been updated yet.
Same on WEB15.
Another thing, links in emails have double slashes (geocaching.com//seek & geocaching.com//pocket). Links do work with double and single slashes.