What is Microsoft Defender Quarantine?
Microsoft Defender Quarantine is a feature that is integrated with Outlook to protect users from harmful emails and spam. It automatically holds suspicious emails in quarantine until the user can review them and decide whether to allow them to be delivered to their inbox or to delete them.
By enabling Defender Quarantine on the Outlook client, OIT is empowering end users to release messages they previously would not have seen.
Is Microsoft Defender enabled for my email?
Yes, Microsoft Defender Quarantine was enabled campuswide on June 6, 2023.
What's the difference between quarantine and the junk email folder?
The junk email folder is only intended for email that is considered "bulk" email (such as surveys or advertisements), while quarantine is intended to prevent harmful emails from ever reaching your inbox. Occasionally, emails that are not harmful could end up in quarantine, but over time Microsoft is working to improve their detection techniques.
How long do messages stay in quarantine if I take no action?
Quarantined items are available for 30 days. After 30 days, these emails expire and cannot be reviewed or released.
How often will I receive an email notification to check my quarantine?
You will receive a notice daily, but you can check your quarantine at any time by visiting https://security.microsoft.com/quarantine.
I don't want a daily quarantine reminder. How can I stop that notification?
We don't currently have an opt-out process for quarantine notifications; however, you can use Outlook to create a rule to automatically delete these emails. Use our inbox rule tutorials for Outlook on the Web or Microsoft Outlook Desktop to learn how.
How often should I check my quarantine? Do I have to take action on every email?
We recommend checking your quarantine regularly to ensure that no legitimate emails are being blocked. If you ignore quarantined emails that you don't want to receive, those emails will expire and be deleted automatically after 30 days.
How do I preview an email in quarantine?
To preview an email in quarantine, log in to https://security.microsoft.com/quarantine, select the email, then click the Preview button.
How do I release an email from quarantine?
To release an email from quarantine, log in to https://security.microsoft.com/quarantine, select the email, then click the Release button, if available. The email will then be delivered to your inbox. Messages may also be released directly from the quarantine notification emails.
If a message is determined to have a high probability of being harmful, it will require OIT administrator intervention before being released to your inbox.
How do I delete an email from quarantine?
To delete an email from quarantine, log in to https://security.microsoft.com/quarantine, select the email, then click the Delete button. Messages may also be deleted directly from the quarantine notification email.
What is the safe senders list?
The safe senders list is a feature used in Microsoft Defender Quarantine to ensure that emails from specific senders are not placed in quarantine. This feature can be useful for safelisting emails from known business partners, colleagues or other important contacts.
While the safe senders list can help reduce the chances of legitimate emails being quarantined, it doesn't guarantee that all emails from those senders will be safe, so it's still important to review your quarantine regularly and be vigilant against potential phishing or malicious emails.
How do I add a user to my safe senders list?
- Log in to your Outlook Web Account.
- Click the Settings icon in the top right corner of the screen.
- Click View all Outlook settings.
- Click Mail.
- Click Junk email.
From this menu, you can search for, add and delete users from your safe senders list.
While Microsoft claims that domains may be added to the safe senders list, users must currently add specific email addresses to the safe senders list.
What should I do if I routinely see messages from a verified sender in my quarantine or if I accidentally block a legitimate email address?
Legitimate messages may appear in quarantine if the sender was accidentally placed on your blocked senders list.
To unblock a legitimate sender:
- Log in to your Outlook Web Account.
- Click the Settings icon in the top right corner of the screen.
- Click View all Outlook settings.
- Click Mail.
- Click Junk email.
From this menu, you can search for, add and delete users from your blocked senders list. We recommend that you review your blocked senders list regularly to ensure that no legitimate emails are being blocked.
Why do some of the emails in quarantine only allow "Request Release" instead of direct release to my inbox?
If a message is determined to have a high probability of being harmful, it will require OIT administrator intervention before being released to your inbox. Please allow one business day for these emails to be reviewed and, if they were false positives, released to you.
Can I block a specific user or email address from sending me emails?
Yes, you can block a specific user or email address in the Quarantine tab, which will prevent any future emails from that user or address from being delivered to your inbox. You can also right-click emails in your inbox and select either Block > Block Sender, or Junk > Block Sender, depending on your client. Visit our Edit your safe and blocked users list tutorial for screenshots of this process.
What should I do if Microsoft Defender Quarantine is over sensitive or quarantines emails I send?
Please contact the IT Service Center at 303-735-4357 or oithelp@colorado.edu.
