How to set the phishing email threshold in Microsoft 365?
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The phishing email threshold in Microsoft 365 Defender is a setting that determines the sensitivity level at which emails are classified as phishing attempts. By setting this threshold, you can control how aggressively Microsoft 365 Defender filters out potential phishing emails.
- 1 - Standard: This is the default setting. It means the severity of the action taken on a suspicious email depends on the confidence level (low, medium, or high) in identifying it as a phishing attempt. For example, if it's very high, it takes strong action, but if it's low, the action is less severe.
- 2 - Aggressive: With this setting, if an email is flagged as phishing with a high level of confidence, it's treated as a very clear phishing attempt, and strong measures are taken.
- 3 - More aggressive: If an email is flagged as phishing with medium or high confidence, it's treated as a very clear phishing attempt, and strong action is taken.
- 4 - Most aggressive: All emails flagged with low, medium, or high confidence are treated as clear phishing attempts, and strong action is taken with this setting.
Here's how to set the phishing email threshold in Office 365:
- Sign in to the Microsoft 365 Defender portal.
- Go to Email & collaboration > Policies & rules > Threat policies > Policies > Anti-phishing.
- Select the 'Office365 AntiPhish Default (Default)' policy.
- Under 'Phishing & threshold protection', choose 'Edit protection settings'.
- Adjust the 'Phishing email threshold' slider to set the value.
To set the phishing threshold value using PowerShell, you can use the following cmdlet. This approach can help avoid the manual navigation of multiple admin portals.
Set-AntiPhishPolicy -Identity "Office365 AntiPhish Default" -PhishThresholdLevel "ThresholdValue"
Replace with your desired threshold value between 1 and 4. This command will update the phishing threshold level of the default anti-phishing policy.
IMPORTANT: The threshold value is 1 for the default policy, 3 for the standard policy, and 4 for the strict preset security policy. Keep in mind that increasing this value raises the chances of false positives (good mail marked as phishing). Set the phishing email level threshold at 2 or higher based on your organization's requirements.