I do the same, but some companies don't seem to be interested. I've had two different emails linked to a magazine's website and had spam to both.
When I've contacted them about it, they've been absolutely adamant that the spammer must have (twice) guessed the exact email address that I've had there.
When I've contacted them about it, they've been absolutely adamant that the spammer must have (twice) guessed the exact email address that I've had there.