If you’re a Gmail user, you probably also have a Google+ account. Well with the new Gmail update that now means that unless you opt out any random individual that is also a G+ user can send you a message aka spam you.
Although it doesn’t mean they will have your Gmail account it just means they can message you however if you respond they will then have your email address.
Watch this video where its explained and how to turn off the settings because I’m sure you already have enough spam as it is without wanting more to have to deal with.
Another great one from the guys at Huff Post Live