- KnowBe4 Prevent
Best for: Teams worried about misdirected email
It earns a place because it targets human mistakes, such as the wrong recipient or the wrong file, and it warns the sender in Outlook before the email leaves. That fits a Microsoft 365 company whose main worry is careless sends, though it also flags deliberate ones. Weigh how often users will see a warning in a normal week, because a prompt people learn to click past stops protecting you.
From Best Email DLP Solutions for Business, Fall 2026
