Once you receive any random email starting with “ Congrats you have won…” “Congrats! You are part of..” they are scam, a dumb one to be precise but they know some people will still fall for it anyways.
For the OP, did he participate in any giveaway or promotion? If he did, that means it was a scam giveaway or promotion and if he did not then it's obviously a scam move, no company will give out free money for nothing, I think the dumbest of all crypto users wouldn't fall for this pattern of scam.
To be frank, I didn't participate in any giveaway or bounties somewhere, i stopped doing bounties or airdrops long time ago and it's been long also that I received promotional mails.
The reasons why I quickly knew it was scam is because, "I get a mail from a source I didn't participate in" I don't usually trust something like this, I have to participate in activities while I receive the follow up mails, that's how things work."
This is also similar to many corporate companies in Nigeria, where a random MTN user will receive a call to have been gotten appointment to work in a company while the user do not submit any CV anywhere.