Hi Diana Watts and Sanford Whiteman, Thanks for replying to my question. When I said that the email address looks correct, I mean that via one-to-one communication with these bounced emails, we do get a reply, however, when we send them communications via Marketo campaigns, they bounce. It might be important to note: We don't have a dedicated IP, we're on a shared one. Some bounce codes I'm seeing are: 554 sender is rejected: 16 550 Mail could not be processed 550 Denied by policy 550 5.7.1 <em-sj-02.mktomail.com[199.15.214.202]>: Client host rejected: Connection rejected due to site policy 554 ESMTP not accepting messages 554 sender is rejected: 63 Sanford, I do understand your reasoning for not requesting to be whitelisted, but worth a try, right? I'm going to continue to try to build the smart list based on this /blogs/marketowhisperer/2015/08/18/monitoring-email-deliverability-troubleshooting-spam-blocks-part-iv. Thanks! Danielle
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