When you are setting up an email campaign, you will be prompted to enter the suffix of your company or organization's email address (the web address that follows the @ in the email address).
You may see orange bars appear under this field. This means that your domain is in the process of being verified.
To ensure that your emails are being sent to all of the users on your Email List, it is recommended that you authenticate your email address domain with DomainKeys Identified Mail (DKIM). Find out how to authenticate your domain here.