Got three emails from these, Stellar airdrop for BTC and BCH owners, offering free crypto coin but I wasn't able to find anything about them on the web. So bells are ringing.
Mind providing some screenshots?
The fact that it was 3 emails I doubt all of them are legit. In blockchain Stellar airdrop for example, I only received 1 email but supposed to be 2 I guess since the first email was about the wait list. Never received follow up email since then. Don't know about the others.
Well too early to conclude so give us more details here.