I am willing to bet $20 he is a scammer.
You can tell alot by the way the incoming email is worded. If it is full of spelling mistakes, grammatical errors, and broken english, I would just delete it. My guess is that legitimate customers from the UK would have a firm grasp of the english language and be able to compose a proper sentence.
HA! That would mean we'd have to delete half the posts that people make on this board!
-Tim