I have a Gmail account. Today, I had received a spam message whose subject line was actually "[SPAM]". Is this some new kind of "trick" by spammers, or was the subject line determined to be 100% sure SPAM and thus marked as such by Gmail or "something else"? And if so, what is "something else"?
Technical detail: I don't have any post-processing on my side; I fetch the e-mails directly from Gmail via IMAP.
While spammers arent the smartest people on the planet, they probably arent adding [SPAM] to their email.
More than likely, an automated spam filter is detecting the email as spam and adding it to the subject line. This allows the email to go through, and let the recipient set up filters to deal with the spam.
In a previous company I worked at, we couldnt risk not getting an email and miss something important. We set up a spam filter than would add asterisks (*) to email. The more likely the mail was spam, the more asterisks it got. This allowed the recipient to tune his/her email to their preference on what spam came into their inbox and what they would check later.
