Ah, I see. BrickLink is an American website, that was bought by LEGO recently, and they allow anyone worldwide to open a storefront to sell LEGO. We just happen to both have registered to sell stuff, me in Brooklyn, them in Germany.

It's the second time someone uses my BrickLink email address to send me spam, and while the first was from a US seller who got my email address from a legitimate order I placed with them, I don't know where this German seller got my email address.