URL rewriting is a security feature in which links in incoming emails are rewritten by the email security gateway. When a recipient clicks a link, they are first routed through a scanning service that checks the target page for malware and phishing. In an ISMS, URL rewriting is a technical control against email-based attacks. It adds a time-of-click protection layer on top of spam filters and attachment scanning. Common products offering this capability include Microsoft Defender for Office 365 and Proofpoint.