I am sure most of your are too savvy to fall for this one but there is a fairly convincing HMRC email phishing email claiming that there is a refund waiting for you. It looks fairly legit (apart from "Mother Maiden Name") bad english is usually an indication of a phish like this.
Anyway fyi HMRC themselves say "HMRC wi l l never s end notifications of a tax rebate / refund by email, or ask you to disclose personal or payment information by email."