Outlook Quarantine filter

Quarantine behavior is controlled by Exchange Online/Defender for Office 365 policies, not by Outlook. Outlook cannot turn off or bypass quarantine.

In Microsoft 365 cloud mailboxes, quarantine is always used for certain threats:

• Malware detections by anti-malware policies
• Malware or phishing detections by Safe Attachments policies
• High confidence phishing detections by anti-spam policies

These categories are always quarantined to protect the service and cannot be completely disabled. Admins can only reduce how often other messages are quarantined by changing the action for spam/phishing from “quarantine” to “move to Junk Email folder” in anti-spam and anti-phishing policies. Outlook itself has no setting to stop messages being placed in quarantine once the service has decided to quarantine them.

So:

• Outlook cannot stop grouping messages into Quarantine.
• An Exchange/Microsoft 365 admin must adjust anti-spam/anti-phishing/anti-malware or preset security policies if fewer messages should be quarantined, but malware and high-confidence phishing will still be quarantined.

References:

• Quarantined email messages in cloud organizations