I use Gmail and Chrome with Windows7. I'm not saying they're the best in the world but it does take care of spam quite efficiently on it's own.
I rarely get Spam in my Inbox.
On the few times I do I just click the icon marked 'this is spam' above the message.
Of course there are always a few dedicated sites that will get through---- even those I've asked to remove me from their mailing list!
But by and large I have almost no spam sent to my Inbox. I'm sure different browsers, email types, OSs, preferences etc. will react differently. That's the 'beauty' of the Internet.
The thing with DS (when the notifications were going to my Spam folder) was easily fixed by just adding DS to my contact.
Funny thing, though---- when I first joined DS I was getting notifications in my Inbox. Then that stopped. I guess how 'things' operate at sites are constantly changing.