How can I stop Dropobox from spamming me?

For the last few hours I've been receiving apprpx 1 spam email per hour from the email address community@dropboxforum.com with the subject line "You have earned a new badge in The Dropbox Community!"

How can I stop this, short of blocking  that email address completely in my email account? 

I'd rather not block it completely if there's any other way but I don't want to receive another spam from them.

Dave