What kinds of email messages might be quarantined?
Microsoft Exchange Online Protection (EOP) automatically scans messages messages and attachments for potential security and spam issues. Messages that are deemed as a threat or spam are sent to quarantine. EOP sends an email titled "Microsoft 365 security: You have messages in quarantine" to your inbox daily with messages that are caught in quarantine. Follow the instructions in "Viewing Quarantined Emails in Outlook.com" to view these messages and adjust the spam filters.
While EOP blocks known spam, phishing, and virus or malware infected messages, others messages may be quarantined if it detects potential issues:
- Similarities to known spam or malware. A combination of triggers including keywords, all or part of the sender's address, or bulk activity can cause messages to be quarantined.
- Certain attachments, especially with executable files (programs) will be quarantined.
The following are NOT quarantined:
- Messages sent to and from official CUIMC and affiliate email addresses (NYPH, CU, Cornell), or institutional mailing lists will NOT be quarantined - unless known virus, malware or spam activity is detected, or a password-protected or encrypted file is attached.
- Known spam, phishing or infected messages will be blocked completely and will not appear in your quarantine or mailbox at all.