What everyone else has said. Although you do need to be careful with unsubscribe. If the site is not legit, it only tells the spammers that you are alive.
Most of my mail comes through Yahoo and I find the spam filter quite good. Sadly blocking a lot of these addresses is a waste of time because they are one time addresses.
When giving out email addresses I have a few rules.
If they are not going to send me a subscribe link, then they get
noddy@toytown.com which equates to "you don't need to know". BTW toytown.com is a valid domain, god knows how much spam noddy gets.....
If they want me to subscribe and I have to response to a subscribe link, then they get a sink gmail account which I rarely if ever bother to read the mail on. Mainly to empty it.
If I want to subscribe to something which I want notification to be sent to me, then I give one of my 4 main email addresses.
It mainly works for me.
To understand the scale of this, Linde Gas blocks about 1.5 billion spam mails a quarter...