In order to choose which publishers are able to contact you, please click on the Account tab from the top of our homepage. From there you can click on the tool to "Select how I wish to be contacted by publishers" tool in the E-Mail notifications section.
On that page, you can choose your default options that will apply to all publishers as well as set individual publishers different from the default settings if you like. Once done, be sure to hit the Save Changes button to keep your choices.