We have seen some emails not be deliver due to its content or even the subject line. Are you or any of these contacts able to receive a blank test with an altered subject line? Not only this, but I took a look and can see all of the email address sent this campaign have the same domain. private domains like this do tend to have stronger filter settings running. Because of this I would suggest having your IT department whitelist Constant Contact in your security settings. Are you or any of your company's leadership able to receive your email after whitelisting?