Updated September 23, 2025: We have updated the timeline. Thank you for your patience.
We’re introducing a new visual indicator in the reading pane of Outlook Mobile (iOS and Android) to help users identify messages from unverified senders. This feature aligns with existing functionality in Outlook for desktop and web, bringing a consistent experience across platforms. When a message is from a sender we couldn’t verify as safe, users will see a banner in the reading pane warning them to be cautious.
This message is associated with Microsoft 365 Roadmap ID 491471.
When this will happen:
General Availability (Worldwide): We will begin rolling out mid-July 2025 and expect to complete by late October 2025 (previously mid-September).August 2025.
How this will affect your organization:
When users receive an email from an unverified sender, they will see a banner in the reading pane explaining why the sender is flagged and warning about potential impersonation. This complements existing safety messages such as:
- “External sender”
- “Not on safe senders list”
- “You don’t often get email from this sender”
This feature is available by default when the unverified signal is received by the service. There are no admin controls to configure or disable this functionality.
What you need to do to prepare:
No admin action is required. However, we recommend informing your users about this new visual cue and its purpose. If your organization provides internal training or documentation on email safety, consider updating it to include this new banner.
Learn more: Phishing and suspicious behavior in Outlook