An authentication method that requires a human to respond to an email challenge message before the original email that triggered the challenge is delivered to the recipient. This method is sometimes used to cut down on spam since it requires an action by a human sender.
Combining Email Marketing with Other Types of Marketing
Whether you choose to do your marketing online or offline, one thing does not change. This is the concept that no single marketing strategy will be as effective as a combination of two or more marketing strategies.
