What to do if an email with a confidential attachment was sent to a masked SAP address and needs to be recalled?
Matthew Whittaker
Co-founder & CTO, Suped
Published 17 Jun 2025
Updated 15 Aug 2025
7 min read
Sending an email with confidential information to the wrong address is a serious concern, particularly when it involves sensitive data and masked domains, like those used with SAP through a system like Salesforce Marketing Cloud (SFMC). The immediate reaction is to recall the email and delete the attachment. However, the effectiveness of email recall features is often limited, especially when dealing with external or specific service-masked domains.
Understanding what steps to take, and what is realistically achievable, is crucial for damage control and maintaining data security. This guide will walk you through the process of investigating, mitigating, and ultimately preventing such incidents.
Understanding email recall limitations
Email recall functionality, like that offered by Microsoft Outlook, primarily works within the same organizational email system (e.g., an Exchange server). If the recipient is outside your immediate network, or if the email has already been opened, the recall attempt is unlikely to succeed. Most email systems do not allow senders to remotely delete emails from external inboxes once they've been delivered.
The challenge intensifies when the email is sent to a masked SAP address, such as an @xxx-email.com domain. These domains are often set up by email service providers (ESPs) like Salesforce Marketing Cloud (SFMC) to handle email routing and tracking on behalf of your primary domain. While this masking can improve deliverability by separating marketing sends from transactional ones, it adds a layer of complexity when an email is misdirected.
Unlike internal emails that might reside on your corporate server, emails sent to these masked addresses are handled by the ESP. This means you lose direct control over the message once it leaves your organization's immediate network, making traditional recall methods ineffective. The primary goal shifts from recalling to understanding delivery status and mitigating potential data exposure.
Investigating the masked SAP address
When an email is sent to a masked SAP address, especially one managed by an ESP like SFMC, the first step is to trace its path. Since the masked domain acts as an intermediary, simply checking your Outlook sent items won't tell you the full story. You need to investigate where the email was routed by the ESP. Here's a suggested approach.
Begin by consulting your internal IT or email administration team. They can check your organization's mail logs to see if the email was successfully handed off to the SFMC domain. Look for delivery receipts or bounce messages. If there's no bounce, it usually means the email was accepted by the receiving server, which in this case would be SFMC's infrastructure.
The most crucial step is to contact SFMC support (or the support team for your specific ESP handling the masked domain). They have access to detailed logs regarding emails sent to and from domains they manage. They can confirm if the email reached the @xxx-email.com address and what happened to it afterward. This includes whether it was delivered to a specific mailbox, routed elsewhere, or dropped. This is the only way to get definitive answers about its fate. SFMC support can help clarify how those masked email addresses are configured.
Investigating email delivery
Internal logs: Check your own mail server logs for delivery status of the email to the masked SAP domain. Confirm if it was accepted or rejected by SFMC's servers.
Contact ESP support: Engage with SFMC support. Provide them with email headers, sender, recipient, and timestamp. They can track the email within their system and confirm delivery, bounces, or redirects.
Review SAP configuration: Understand how the masked SAP email addresses are configured within SFMC. Do they forward to an actual inbox, act as a black hole, or serve a different purpose?
Immediate steps and damage control
Even if recall is impossible, immediate action is necessary to minimize the impact of the data exposure. This involves a multi-pronged approach focusing on internal reporting and, if necessary, external communication.
First, inform your internal security and legal teams. This is a potential data breach, and your organization likely has a protocol for handling such incidents. Prompt reporting ensures that proper legal and compliance steps can be taken. They can guide you on reporting requirements and help assess the risk based on the confidentiality level of the attachment.
If it is confirmed that the email was delivered to an actual, unintended recipient, and especially if it contains highly sensitive information, direct communication may be necessary. Draft a polite and professional apology, requesting the recipient to delete the email and its attachments without opening them. Be prepared for potential pushback or no response. Remember that for general Gmail or Outlook recipients, un-sending is usually not an option.
Finally, ensure your internal processes are updated to prevent recurrence. This might involve reviewing sender permissions, implementing stricter data loss prevention (DLP) policies, or enhancing training on handling confidential information and verifying recipients before sending. For more general advice on what to do, see our article on what to do after accidentally sending an email.
Preventing future incidents and protecting reputation
What you can do
Internal logging and tracing: Check your organization's mail transfer agent (MTA) logs to confirm successful handover to the ESP.
Contact ESP support: Leverage your ESP's (e.g., SFMC) support team to investigate the email's delivery status within their system.
Inform security/legal: Immediately report the incident internally as a potential data breach. This is critical for compliance.
Communicate with recipient (if known): If the recipient is identifiable, send a polite request to delete the email and attachment.
What you likely cannot do
Outlook recall: Attempting an Outlook recall will almost certainly fail for external recipients or emails sent through ESPs.
Remote deletion: You cannot remotely delete an email or its attachment from the recipient's inbox once it has been delivered.
Undoing delivery: Once an email is delivered, especially to a live mailbox, it is considered out of the bag, and its contents are exposed.
Recovering from such an incident also involves addressing potential impacts on your sender reputation. While a single accidental send may not immediately trigger a blocklist (or blacklist) listing, consistent misdirection or data breaches can lead to deliverability issues. Monitoring your email domain and IP reputation and proactively checking how your email address ends up on a blacklist can help you stay ahead of potential problems.
To prevent future accidental sends and potential data leaks, it's essential to implement robust email security and deliverability practices. Start by ensuring all users are well-trained on email etiquette and the importance of verifying recipient addresses. Emphasize caution when sending emails with sensitive attachments, especially outside regular contacts or internal systems. You should also ensure your email authentication protocols (DMARC, SPF, DKIM) are correctly configured to prevent spoofing and ensure legitimate emails are recognized.
Consider implementing data loss prevention (DLP) solutions that can scan outgoing emails for sensitive content and block or encrypt messages before they are sent to unauthorized recipients. These tools can be invaluable in preventing confidential data from leaving your organization's control. Regularly audit your email sending processes and update policies based on new risks or incidents. For insights into common email deliverability problems, review why your emails might go to spam.
Views from the trenches
Best practices
Always verify the recipient's email address multiple times, especially for emails with confidential attachments. Double-check auto-complete suggestions.
Implement internal policies requiring peer review for sensitive email sends outside the organization or to unfamiliar addresses.
Utilize data loss prevention (DLP) tools to automatically detect and prevent sensitive information from being emailed.
Educate employees on the risks of accidental data breaches and the importance of secure email practices.
Common pitfalls
Assuming Outlook's email recall will work for external recipients or masked domains, leading to a false sense of security.
Failing to immediately report an accidental send to internal security and compliance teams, delaying necessary mitigation steps.
Not understanding how masked email domains (like those from SFMC/SAP) route emails, leading to confusion about delivery status.
Neglecting to update internal email sending protocols after an incident, making recurrence more likely.
Expert tips
If an email containing confidential data is sent to a masked SAP address managed by an ESP, the most effective approach is to contact the ESP's support directly.
The ESP's internal logs are the authoritative source for determining whether the email was delivered or absorbed by their system.
For critical incidents, a prompt internal data breach notification is as important as investigating the email's delivery.
Proactive measures like robust email authentication and user training are the best defense against accidental data leaks.
Marketer view
A marketer from Email Geeks says to confirm what the masked domain (like xxx-email.com) is and how it is hosted, especially if it's an address you'd normally expect to deliver email to.
2020-11-24 - Email Geeks
Marketer view
A marketer from Email Geeks says that if an email was sent as a regular message and no rejection has been received, it was likely delivered, and remotely deleting the message outside specific enterprise systems is not possible.
2020-11-24 - Email Geeks
Addressing accidental email sends
Accidentally sending a confidential attachment to a masked SAP address or any unintended recipient is a significant incident that requires immediate and systematic action. While email recall features offer limited effectiveness for external or masked domains, understanding the mail flow through your ESP (like SFMC) is critical for determining delivery status.
The key is swift investigation with your ESP's support, prompt internal reporting to security and legal teams, and proactive communication with the unintended recipient if direct exposure is confirmed. More importantly, implement robust preventive measures, including enhanced user training and data loss prevention technologies, to safeguard your organization from future incidents and protect your sender reputation.
Outlook recipients, un-sending is usually not an option.
