"Using double opt-in forms on websites, blogs, social media pages and anywhere prospective recipients may be looking to stay in touch with you is a must," says Paul Turnbull, product marketing manager at . Double opt-in means the system sends a confirmation request to the submitted email address, requiring the owner to take an action-usually click a link in the email-to confirm that they are the email address owner and want to subscribe to the mail list.

"In today's highly connected world, consumers want to connect with businesses in a variety of ways: email, social media, mobile and more. As a result, businesses need the ability to reach consumers wherever they are," says Ron Cates, director of new market development at . Outside of using traditional tools to grow your email list, there are many unique and interesting options. These include "placing a sign-up form or guest book at your place of business and adding a Join My Mailing List button to your website and your Facebook page," Cates says. In addition, there are for signing up to stay connected with businesses or organizations from virtually anywhere. For example, Constant Contact offers Text-to-Join, in which users are added to an email list after sending a text message to a designated keyword, and Scan-to-Join, which lets customers join a list by scanning a QR code that a business has placed on a flyer, business card or other printed media, he says.