On Wednesday, 15 August 2012 14:18:55 UTC+1, Rob Miller wrote:
I recently tried to sell a clinical glass mercury thermometer, which only
contained a very small amount of mercury, and that triggered the following
email from the 'Elf 'n' Safety Brigade:

Dear ...

Please reply to this email and provide me with your email
address

Hang on. Either he already has your email address, or he doesn't - in which case you aren't going to get the email! (or was this actually an eBay, or similar, "secure message"?)