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