Letter finally received by the White House UPDATE:

There must be some security delay in sending mail to the White House. I finally got back the green postcard for the certified letter. It was delivered 3/27/2017 as you can see from the stamp and probably now is going through whatever processing mail goes through once it reaches the White House.  So there might be a response during this coming week.

UPDATE: As of 5/14/2017 I have not heard back.