MailChimp Messages Not Delivered
If messages are not arriving, the most likely explanation is that they are being erroneously blocked by an email spam filter before they reach the recipient.
When blocked by a spam filter, the email may end up in a local spam folder in Outlook, Apple Mail, or that person's web-based email client. In those cases, it is possible to mark the message as "Not spam," which often resolves the issue. In other instances, the email is blocked by the recipient's IT group before it ever reaches them.
Once we send the message, we don't have control over the recipient's organization email delivery. The next step would be for the recipient to contact their IT group to report that the messages are being blocked as spam, and seek IT assistance in resolving the issue. Our email mailing list provider has an article to assist:
We're happy to help if the IT group needs more information from us.