Blame either the makers of PockerPC or the makers of Outlook for that. You'd almost think they're conspiring to prevent people from being able to switch.
But, you can't conspire with yourself! See, e.g., COPPERWELD CORP. v. INDEPENDENCE TUBE CORP., 467 U.S. 752 (1984) ("We hold that Copperweld and its wholly owned subsidiary Regal are incapable of conspiring with each other for purposes of 1 of the Sherman Act.") http://www.justia.us/us/467/752/case.html