Anyone who uses email will receive SPAM, or unwanted emails. Some will be from ‘Nigerian princes’ or ‘Lawyers representing someone who wants to give you money’. These are all, of course, poor attempts to part you from your hard earned money. Some SPAM emails are less obvious in what they are trying to do though. Have you ever received an email asking you to buy (for example) watches or other quite reasonable, but unwanted, products? You ignore the first email, and then you get another one a few days later. You might ignore that one as well but eventually you will get tired of seeing them and notice an unsubscribe option at the bottom. Hurrah you think, I’ll unsubscribe and stop them coming.
Unfortunately, if you click on unsubscribe what you might unwittingly do is increase the value of your email address to other spammers. Spammers buy email addresses – unconfirmed ones are cheap, but an email address that has received a response of any kind is more valuable and so, instead of reducing the emails you receive, the unsubscribe option in these cases can result in you receiving far more.
Naturally, most of the emails with an unsubscribe option are genuine since it is an EU requirement to allow people to opt out easily, but the ones to watch for are those from places you have never signed up for or even dealt with.