I also noticed that it still can be purchased, along with several other products that are "phased-out". The difference may be full vs "activated TBYB". With full versions they send the serial number to you in your confirmation/download email.
To email corel, you need to first go to their Knowledge base
. Click on one of the subjects, and there is one or two concerning activation. Clicking on an answer should reveal a tab that states Email Corel
Click on image to enlarge
I think that Corel MediaOne replaced PhotoExpress. Corel also has PhotoImpact, and their flagship program Corel Draw Graphics Suite.