For years, organizations worried about users sending the wrong attachment to the wrong person.
A confidential spreadsheet accidentally emailed externally. Sensitive HR information sent to the wrong recipient. A pricing document shared with the wrong customer.
These mistakes happen every day and can lead to accidental data exposure, compliance risks, and costly security incidents.
But email habits are changing.
Today, Microsoft 365 users increasingly share files from OneDrive and SharePoint instead of attaching documents directly to emails. Outlook often encourages this by converting attachments into cloud links and shared files.
Many users see these shared files as safer alternatives to traditional attachments.
However, there is an important reality:
Shared files are often simply replacements for attachments — and they create many of the same risks.
OneDrive Shared File Risks: The New Attachment Problem
Cloud sharing has changed how files are sent, but it has not removed human error.
When sending OneDrive or SharePoint files through Outlook, permissions can be granted automatically as the message is sent.
If the wrong recipient is included in the email, you may unintentionally give that person access to the file.
Common examples include:
- Sharing pricing information with the wrong customer
- Accidentally sending internal documents externally
- Exposing confidential healthcare or financial information
- Sharing project files with unintended recipients
The issue is not malicious attacks.
It is accidental file sharing in Outlook caused by simple human error.
Whether users attach a file or share a OneDrive link, the core question remains:
Was this file intended for these recipients?
Shared Files and Attachments Carry Similar Risks
Organizations often invest heavily in:
- Spam protection
- Malware prevention
- Email security gateways
- Data Loss Prevention tools
- Microsoft 365 security solutions
These tools are important.
But many email incidents happen because someone simply clicks Send too quickly.
Whether a user sends:
- Traditional attachments
- OneDrive shared files
- SharePoint document links
…the risk remains the same:
Sending sensitive information to the wrong person.
This is why organizations increasingly look for ways to prevent accidental file sharing in Outlook before messages leave the organization.
SendGuard Helps Prevent Accidental File Sharing in Outlook
SendGuard already helps organizations reduce accidental email disclosure by warning users before emails are sent.
SendGuard can prompt users to review:
- Attachments
- External recipients
- Sensitive information
- Missing attachments
- Organization-specific policies
Now SendGuard also recognizes OneDrive and SharePoint shared files.
Before the message is sent, SendGuard can detect shared files and ask users to confirm them.
Users can review:
- Which files are being shared
- External recipients
- Shared files and attachments together
- Who the email is going to
This creates a final confirmation step before sensitive information leaves your organization.
Modern Outlook Security Must Include Shared Files
Attachments may be changing into shared links, but the risk of accidental email disclosure remains.
Organizations focusing on Outlook shared file security should recognize that cloud sharing has changed the format of attachments—not the human behavior behind mistakes.
If users can accidentally send an attachment to the wrong person, they can accidentally share a OneDrive file with the wrong person too.
SendGuard helps organizations prevent accidental file sharing in Outlook by providing a final send-time review for recipients, attachments, and shared cloud files.
Because replacing attachments with links does not remove human error.
It simply changes its format.