Let me get this straight: when a random foreigner sends a letter to a political party, Chunghwa Post is supposed to send it to MOFA instead of the addressee?
Or was this a clueless foreigner who addressed it to MOFA thinking the KMT was still in power? 
They sound more like the CCP with how they react everyday.
Why would anyone put “Chinese Nationalist Party” on an envelope instead of KMT or whatever the characters are? A simple check with the Google would have solved that.
Hell, I am a clueless foreigner and I could have done that.
I get it–中國國民黨， Chinese nationalist party–but since when are they using that?