Hi! I understand your concern about MailPoet messages showing up as “This message has no content” in Outlook. This usually happens because Outlook has stricter rendering rules compared to other mail clients and may block messages that rely mainly on remote images or unsupported formatting.
To address this, I recommend ensuring your messages always include some plain text content, avoiding background images or unsupported HTML styles.
If the issue persists, please test by sending a simplified plain text email from MailPoet to confirm whether Outlook can display it. If plain text works, then the problem lies in the formatting of your template.