Prevent spam or phishing attempts from external chats in Microsoft Teams

When Teams detects potential spam or phishing activity (also known as impersonation) from someone requesting to chat with you from outside your organization, you’ll see a notification.

Impersonation is a common type of cyberattack where the sender adopts the identity of a specific person or entity with the intention of deceiving the recipient.

When you see the following screen in a one-on-one chat or group chat, please take these actions to ensure your security:

👁 Screenshot showing the warning message that appears when Teams suspects an external contact may be attempting to spam, phish, or impersonate.

1. Double-check the sender’s identity, including their name and email address.
2. Preview the message and check for anything that looks unusual or suspicious.
3. Only accept the conversation if you’re sure the sender is trustworthy.

Choose Accept if you trust the sender. Choose Block to stop receiving any Teams communications from them.

Related topics

Accept, block, or delete chat or meeting requests from people outside your organization