Overall I found your response rather cynical. Implying law being broken is required for a previous comment to be a valid point is harsh. There's campaign law and there's ethics. Just because some behaviour was never codified into law doesn't make it right.

Having said that, I think the ethics of this political strategy depends on the intentions. If a politician has true respect for the people, wants to give personal touch, and just doesn't have enough time to handwrite the letters - that's okay in my view. If a politician is purely looking for means of influence - that in my opinion is "not okay".