So many people seem to be making this value proposition -
"Give me your name and email address and I'll send you XYZ"
They never mention any other kind of contact. So no one is actually giving them permission to stay in touch.
It's not spam by law. But it's certainly "spam" by how people treat it.
Instead of that you could be saying -
"Give me your name and email address and I'll send you my weekly news letter packed with information about how to XYZ and as a thank you for subscribing you'll receive this report straight away"
So now, they're not only giving you the email address to get the report. They're giving you the email address so you can contact them!
Think of it in the same way as your favourite magazine each month. You happily go out and buy it every month and they advertise tons of stuff to you (not to mention charging you for the privilege).
Imagine how much better your open and click through rates would be...