Manage safe attachments

Microsoft Defender for Office 365 , formerly called Microsoft 365 ATP, or Advanced Threat Protection, helps protect your business against files that contain malicious content in Outlook, OneDrive, SharePoint, and Teams.

Try it!

  1. Go to the admin center, and select Setup.
  2. Scroll down to Increase protection from advanced threats. Select View, Manage, and then ATP safe attachments.
  3. Select your safe attachments rule, and then choose the Edit icon.
  4. Select settings, and then verify that Block is selected.
  5. Scroll down. Choose Enable redirect, and enter your email address or the address of the person you want to review the blocked attachments.
  6. Select applied to, and then select your domain name.
  7. Choose any additional domains you own (such as your domain) that you would like the rule applied to. Select add, and then OK.
  8. Select Save.

Your ATP safe attachments rule has been updated.

Now that protection is in place, you won't be able to open a malicious file from Outlook, OneDrive, SharePoint, or Teams. Affected files will have red shields next to them. If someone attempts to open a blocked file, they'll receive a warning message.

After your policy has been in place for a while, visit the Reports page to see what has been scanned.