How can I get spam emails when my address isn’t listed as a receiver?
Often spam arrives with email addresses in TO: or CC: that are similar but not the same as your address. You can’t find your address in the message – so how did it get to you?
That’s simple – your address is in the BCC line.
One of the many methods spammers use to get past filters is to populate the TO and CC lines with some addresses to make it look (to a spam filter) more like a legitimate message.