To contact one of your affiliates, go to the Affiliates tab in your Social Snowball dashboard. Then, click on the name of the affiliate you wish to contact. You can also search the affiliate by their name, email address, or discount code/link.

This will bring you to the affiliate's profile page. Now, simply click on the Contact button, and an email tab will pop up with the affiliate's contact email preloaded.

To bulk email all of your affiliates, check out this article.