I guess it was a mistake. The email could have a title like lottery ticket instead. Like I have said, it would be a mistake from Bc.game but I expect a site that has many gamblers like it and also having some years of experience not to make such a mistake.
Copy the
https://bc.game link on the email and paste it on a browser to make sure it is truly
https://bc.game.
Sorry to say this but I think you are wrong, what the op complained about is not a mistake on the part of bc.game, they deliberately used that email title to dish out the lottery email to their users who qualify for the free lottery ticket, and the reason they did this is very simple,
To get the attention of the user to not scroll past that email without opening it, and for those who have email notification turned on, they will immediately open the mail as soon as they find it on their notification tab.
Overall, regardless of what ever their reason for doing this is, the truth is that, this is a very poor attitude and scammy in nature, it is only scammers that use such titles to capture the attention of their potential victims to the content they are sharing, Bc.games should desist from such attitude as it doesn't suit them as a big and reputable company.