Depends how careful you are.
Spammers get addresses in a variety of ways, either by fake websites that collect addresses, reading e-mail addresses off websites and forums (this is why you’ll see brian [at] someprovider [dot] com in places, although spammers are wise to this too), and finally just by guessing (aaaa@ aaab@ aaac@ and so on).
So if you’re good about not giving out your e-mail, you don’t publish it on the web and it’s a fairly long or obscure address then you’ll get less spam. Also if you don’t respond to spam, don’t download images and don’t click the ‘unsubscribe’ button then spammers never know the address is valid. Once a spammer knows an address is valid then it’s only a matter of time before it’s passed around other spammers and the volume of junk mounts – at that point you either put up with it or get a new address.
Some addresses are just spam magnets i.e. postmaster@ and webmaster@ any working site because generally these addresses exist and are normally checked.
SD