Virgil from Falconer, New York asks:
What happens to an EMail which I receive and discard as SPAM? Is it buried (filed) somewhere in my computer, is it totally obliterated, is it rejected and returned to the sender? Does the sender of the spam KNOW that I have rejected his message as spam?
Virgil, marking e-mail as Spam (or as not Spam or not junk) is a way of teaching the filter on your account which messages you want to see. Internet service providers usually have a filtering system in place to weed out junk. They usually scan e-mails for certain words or phrases and assign a point value based on the content. They also look for messages coming from suspicious IP addresses. Of course that won’t catch all Spam and sometimes blocks messages you want to see.
If multiple users mark an item as Spam, the filter learns that e-mails from that sender or with that topic are likely Spam and then filters them out in the future. If you’re using an e-mail client, the e-mails are usually treated as if they had been deleted and the trash has been emptied. Usually when you delete Spam from an online mailbox, it’s deleted forever. That means you can’t retrieve them. (At least not reliably and easily. Nothing is ever really gone from a computer unless the drive is scrubbed.)
E-mails really can’t be “returned to sender.” You will get a bounce notice if your email never arrives to the recipient’s mail server and sometimes that contains a copy of the e-mail – but the message you sent doesn’t actually come back to you.
If you have blocked someone’s address, they may get a notice that the message is undeliverable. Otherwise, if a message goes into your Spam filter, the person who sent it may never know.
That’s why it’s important to occasionally check the Spam and Junk folders from your ISP. Even if you download your e-mail using an e-mail client like Outlook, messages could still reside in a Spam folder that you never see in your online mailbox. I once missed a very important business e-mail that way. My online inbox Spam folder contained 400 pieces of absolute junk and three messages from someone who wanted to interview me for a job. Not cool.
Filter are imperfect, so it’s important to help them along by teaching them which messages you want and which ones you’d like blocked.