What it means
Outlook.com's suspicious-link screening checks some email destinations associated with phishing or malicious downloads and can show a warning before navigation. The screening can reduce accidental clicks, but it cannot certify every unflagged link as safe.
A real-world example
A shipping email claims a missed delivery and opens a warning when clicked. The recipient can go to the courier's known website and enter the tracking number without visiting the warned address.
What to do
Stop at the warning, compare the claimed task against the real account through an independently opened app or bookmark, and report messages that fail verification.
The distinction that matters
The exact screening available depends on the Outlook account or subscription. A warning means investigate; no warning means keep normal caution. Microsoft's subscriber guidance explicitly advises against clicking through a triggered suspicious-link page. A real sender may also have a compromised mailbox.
Microsoft's Outlook.com link guidance
