[ScottWhigham]

The downsides of doing this as an interviewer should be easy: if the person disagrees with your comments/ideas, then what? Do you spend the 15-45 minutes crafting the perfect reply email ("I have to defend myself!"), or does the candidate get upset and email your boss with a nasty message like "That guy Scott - he's loony. Know nothing jerk. His comments were wrong - see this MSFT article from 2004 that shows why he is wrong, wrong, wrong!"?

[rorykoehler]

I have always replied with an honestly grateful thank you mail. It's a shame a few insufferable idiots would have the power to change the behaviour of well meaning persons.