Basically, those surveys are after a certain number of responses. It looks like in between you receiving the email and opening it, we got all the responses we needed and ICM closed the survey. We are feeding back to ICM that the messaging doesn't look that smart. It would be nicer to say something like "Thanks for offering to help, but we've now received the number of responses we need." (needs work obviously ;) )
Kelly Dorset
Ex-Plusnet Jobsbody