I think this could be a shorter course to the problem described by loginx above
>>My only concern is really that in the short/medium term, this could lead to a large influx of freeloaders from other communities, who may have no interest in "paying it forward", but mostly in dropping by for a quick freebie, while not contributing anything.<<
Just the email address in caps? I think that's safe enough, could be a convention they fell into. AS long AS he isn't USING caps to emphasize THE wrong WORDS it should be fine.
It could just be a language issue. I don't believe that it's grounds to deny them a shot at a technical interview, nor do I think it's a reason not to employ them if they pass that interview.