Safe Attachments scanning takes place in the same region where your Microsoft 365 data resides. If the external recipients are in a Microsoft 365 organization, then the forwarded messages are also protected by Safe Attachments. Chris receives an email that has an attachment, and then forwards the message to external recipients. Typically, it takes about 30 minutes for a new policy to take effect.Ĭhris's organization has long-standing Safe Attachments policies for everyone in the organization. Jean is protected by Safe Attachments due to that custom Safe Attachments policy. Earlier today, Jean received an email message that included an attachment. Yesterday, an admin in Jean's organization created a Safe Attachments policy that applies to all employees. Lee and the rest of the sales department are protected by Safe Attachments due to the Built-in protection preset security policy that applies to all recipients who are not otherwise defined in Safe Attachments policies. Lee's organization has a Safe Attachments policy that applies only to finance employees. Pat is protected by Safe Attachments due to the Built-in protection preset security policy that applies to all recipients who are not otherwise defined in Safe Attachments policies. Pat's Microsoft 365 E5 organization has no Safe Attachments policies configured. The following table describes scenarios for Safe Attachments in Microsoft 365 and Office 365 organizations that include Microsoft Defender for Office 365 (in other words, lack of licensing is never an issue in the examples).

For instructions, see Set up Safe Attachments policies in Microsoft Defender for Office 365.

You can also create Safe Attachments policies that apply to specific users, group, or domains. For more information, see Preset security policies in EOP and Microsoft Defender for Office 365. Although there's no default Safe Attachments policy, the Built-in protection preset security policy provides Safe Attachments protection to all recipients (users who aren't defined in the Standard or Strict preset security policies or in custom Safe Attachments policies). Safe Attachments protection for email messages is controlled by Safe Attachments policies. Specifically, Safe Attachments uses a virtual environment to check attachments in email messages before they're delivered to recipients (a process known as detonation). Safe Attachments in Microsoft Defender for Office 365 provides an additional layer of protection for email attachments that have already been scanned by anti-malware protection in Exchange Online Protection (EOP).

Microsoft Defender for Office 365 plan 1 and plan 2.

Learn about who can sign up and trial terms here. Did you know you can try the features in Microsoft 365 Defender for Office 365 Plan 2 for free? Use the 90-day Defender for Office 365 trial at the Microsoft 365 Defender portal trials hub.

Office 365 outlook attachment problems