Sorry I've been away for so long. I'm back today with a paradox. I received an email from a website called Zeekler that gave me an account, an account name, a password, and some free resources. Zeekler seems to operate some sort of buying/selling web site. I have never contacted them or requested an account, as far as I know.
I was tempted to log in to Zeekler and close my account, but my instinct is that it would be better to have nothing at all to do with them. I deleted their email (permanently, because it contains a password). I had thought about reporting them as spam when I realized a rather special problem.
First, I hope you know that you should not save emails that contain passwords. In fact, no website should ever send you your password. If one does, you should delete the email with the password permanently at once. Your email account might be hacked some day, and if it is, the hacker will use any passwords in your saved emails to hack your other accounts.
If you successfully report some site as spam, how will you know whether they have sent you another email with a password in it? That's my problem. If Zeekler ever tries to contact me again, I want to know it.
I use Gmail. The way you avoid spam is to mark specific emails as spam. If I had marked Zeekler's email as spam, Google would have saved it in my spam folder, password and all.