Email only visible after using Forward or Reply

Hi Raymond, 

Good day. Thank you for reaching out, and I appreciate you sharing the details of your situation. 

Just a quick note before we continue: this is a user-to-user community forum, so I don’t have access to your Microsoft 365 tenant, your account, or your device to make changes directly. However, I’m here to support you the best I can within these constraints, by providing clear next steps, sharing applicable resources, and directing you to the appropriate support channels. 

Based on the behavior described, the email does not appear to be truly empty, as the content becomes visible when replying to or forwarding the message. This suggests that the issue is more likely related to how the original email body is being rendered in Outlook, rather than an issue with message delivery or EOP filtering.

Since the issue occurs in both New Outlook and Outlook on the web, affects multiple users within the organization, and appears to be limited to messages from a specific sender domain/platform, the issue is likely related to the sender/platform’s email formatting or template. This may include Outlook-incompatible HTML/CSS, an unusual message structure, or formatting that does not render correctly in Outlook.

To help narrow down the cause, I recommend the following checks: 

Some of these steps may require admin rights, so if you do not have the required permissions, please contact your organization’s IT team or Microsoft 365 administrator for assistance. 

1/ Run a message trace for one affected email 

1. Go to Exchange admin center 
2. Navigate to Mail flow > Message trace 
3. Select Start a trace 
4. Search using the sender, recipient, date/time, and subject of the affected email 
5. Review and confirm whether the message shows as successfully delivered and whether there are any indications of filtering, redirection, modification, or rule processing. 

Reference: Message trace in the new EAC in Exchange Online | Microsoft Learn 

2/ Review mail flow rules, disclaimers, and third-party security services 

Even if EOP is not flagging the email, another mail flow rule or third-party service may still be modifying the message after it is received. This could affect the email body or formatting and cause display issues. 

• Please ask your Microsoft 365 administrator to check whether messages from this sender/domain are affected by any of the following: 
  • Exchange transport rules 
  • Organization-wide disclaimers or banners 
  • Signature management tools 
  • Third-party email security gateways 
  • Connector-based mail routing 
  • Link rewriting services, if applicable 

In the Exchange admin center, they can review: 

• Mail flow > Rules 
  To check whether any transport rule is adding disclaimers, banners, signatures, or modifying messages from this sender/domain. 
• Mail flow > Connectors 
  To check whether inbound mail from this sender/domain is routed through a connector or third-party email security service. 

If any service is adding banners, disclaimers, signatures, rewriting links, or changing the message body, it may unintentionally affect the sender’s original email layout. 

Reference: Manage mail flow rules in Exchange Online | Microsoft Learn 

3/ Test the same message in another mail client 

• If possible, try testing the same affected email in Classic Outlook or another mail client. 
• This helps confirm whether the issue is specific to how the message displays in New Outlook/Outlook on the web, or whether the email itself has a formatting issue. 
• If it displays correctly in another client, this suggests a rendering compatibility issue. 
• Otherwise, if it is blank in other clients as well, the sender’s email template or message format may be invalid. 

4/ Contact support 

If everything above appears correct, and there is no evidence that Microsoft 365, EOP, mail flow rules, or a third-party service is modifying the email, the issue may be related to the sender/platform’s email template or message formatting. In that case, I recommend asking the sender/platform to review and correct their email template, if applicable, to ensure it renders properly in Outlook. 

Alternatively, your IT administrator may open a support ticket with Microsoft Support through the Microsoft 365 admin center. They have access to system-level diagnostics and can investigate the issue more thoroughly. At the very least, they may be able to provide the most effective workaround to help ensure the email experience remains smooth and secure. 

In case you do not know who is your IT admin, kindly refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support  

I hope this information is helpful. Should you have any further questions or need additional assistance, please feel free to share them in the comment below. I'm very happy to help.  

Thank you again for your patience and understanding. 

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