Unfortunately, there's not much you can do to stop it. Your address is likely BCC'd and this email is blasted out to tons of people. It's interesting they all have the same "To" address though, so they're likely coming from the same source even though it may not look like it.
You could create a rule to have these deleted automatically. (i.e. If a message is addressed to
witag99877@lukaat.com, then Move to Trash.)
In Mail on iCloud.com, set up rules to automatically filter emails that meet certain conditions.
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