How to Allow Specific Senders to Bypass Blocked Attachments in Microsoft 365
Question details
The administrator wants to allow a small group of trusted external senders to bypass the Microsoft 365 Defender attachment block policy, but the old portal exclusion settings are no longer available.
- Product
- Microsoft 365 Defender
- Device & OS
- not provided
- Scenario
- Administering Microsoft 365 email security policies to allow trusted external senders to deliver blocked file types without disabling global protection.
- Observed behavior
- Microsoft 365 Defender automatically blocks the attachments, and the settings to create per-sender exclusions in the legacy protection portal can no longer be found.
Ensure you have global administrator or security administrator privileges in your Microsoft 365 tenant before attempting to modify organization-wide anti-malware and threat policies.
Use Secure File Sharing Alternatives
Since Microsoft 365 restricts direct bypassing of malware filters for dangerous file types, using secure cloud storage links is the safest method to share these files.
Microsoft 365 anti-malware attachment blocking intentionally does not provide a safe per-sender exception for dangerous file types. Relying on contact exclusions to bypass malware filtering poses a severe security risk.
Ask the trusted external sender to upload the blocked attachment to a secure cloud storage service, such as OneDrive, SharePoint, or a corporate secure file-sharing platform.
Instruct the sender to generate a secure sharing link with appropriate access permissions (e.g., restricted to specific email addresses or protected by a password).
Have the sender email the secure link to your users instead of attaching the file directly. This bypasses the email attachment filter while maintaining file security.
Configure Quarantine Policies for Administrator Review
Instead of completely blocking or whitelisting attachments, route emails with flagged attachments to a quarantine area where an administrator can manually review and release them.
Handle All Your Office Documents Securely with WPS Office
While navigating complex Microsoft 365 email security policies, you can rely on WPS Office as a lightweight, free alternative to create, edit, and securely share your documents. WPS Office offers robust compatibility with Microsoft formats and built-in cloud sharing to help you bypass email attachment limits effortlessly.
- 1. Download the installer: Visit the official WPS Office website and click the download button to get the free installer.
- 2. Install WPS Office: Run the downloaded file and follow the straightforward on-screen instructions to complete the installation.
- 3. Share via WPS Cloud: Open your documents in WPS Office and use the built-in 'Share' feature to generate secure links instead of relying on email attachments.
Frequently Asked Questions
Why can't I find the old protection.office.com portal?
Microsoft has deprecated the legacy protection portal. All email security, anti-malware, and threat protection settings have been migrated to the unified Microsoft 365 Defender portal at security.microsoft.com.
Can I whitelist a specific sender's email address to bypass malware scanning entirely?
No, Microsoft 365 deliberately restricts bypassing malware scanning for specific senders to prevent security vulnerabilities and zero-day attacks. Utilizing secure file-sharing links or quarantine policies is the recommended approach.
What types of attachments are blocked by default in Microsoft 365?
By default, Microsoft 365 blocks file types commonly used to distribute malware, such as executable files (.exe), scripts (.vbs, .bat), and certain macro-enabled documents. The specific list can be viewed and modified within the Anti-malware threat policies.
