Implementing External Email Tagging in Outlook

External email warning tag helps to alert users from clicking malicious links and phishing emails sent by external senders. It plays a vital role in protecting against spam and phishing threats. For these years, admins use a transport rule to prepend in the subject line.

In this blog, let’s discuss implementing an ‘external’ tag identifier on your business email. This feature implements an “External” tag identifier on Outlook for email messages received from outside your organization. Microsoft created this feature in hopes that the external tag will help users easily identify spam and phishing threats from external senders. When someone outside your organization receives an email, an “External” title will be present in Outlook on the web, Outlook for Mac, Outlook for iOS, and Android. After clicking the external tag, the email address for the sender will be shown.

outlook external email tag
Microsoft outlook 365 external email tag

In Outlook clients for Windows, a mail tip will be present at the top of the reading pane.

external email tag in exchange online

If you click the mail tip, it will give you the option to Add a Sender to the Blocked Senders List.

How to turn on the external email tagging feature

Since external tagging is disabled by default, you will need to manually turn this feature on.

  1. Load the exchange online module on PowerShell.
    Import-Module ExchangeOnlineManagement
  2. Connect to Exchange Online PowerShell using an admin account. For example:
    Connect-ExchangeOnline -UserPrincipalName name@imaginet.com
    This will prompt a log-on screen for you to enter your password.
  3. Turn on external tagging.
    The following command will enable external tagging for the whole organization.
    Set-ExternalInOutlook -Enabled $true
    • You could also omit senders and domains from the external tagging feature. For example, to omit admin@fourthcoffee.com
    • I would enter the following:
      • Set-ExternalInOutlook -AllowList admin@fourthcoffee.com
    • To omit a whole domain, use the following example:
      • Set-ExternalInOutlook -AllowList “quest.com”, “google.com” – Enabled $True
    • Adding one domain at a time may throw an exception. A quick workaround would be to add two domains at a time.
    • You could also use the get command below to verify that you have enabled the External tagging feature.
    • Get-ExternalInOutlook

To omit a whole domain, use the following example:
Set-ExternalInOutlook -AllowList “quest.com”, “google.com” – Enabled $True
Adding one domain at a time may throw an exception. A quick workaround would be to add two domains at a time.

You could also use the get command below to verify that you have enabled the External tagging feature.
Get-ExternalInOutlook

Please note that once this feature has been enabled, it may take 24-48 for you to start seeing the External sender tag in email messages received.

Hope this quick tutorial helps you implement the external email identifies tag in your organization and secure your organization from malicious external emails.

Thank you for reading this post! If you enjoyed it, I encourage you to check out some of our other content on this blog. We have a range of articles on various topics that I think you’ll find interesting. Don’t forget to subscribe to our newsletter to stay updated with all of our latest information on Microsoft Stack.

discover more

JIT Pack IO Logo

Managing Open-Source Dependencies with JitPack

Managing dependencies for your Android app has gotten a lot easier with tools such as Gradle, but there is still one big gotcha that it cannot solve: The dependency itself.…

Power BI Blog

Using Microsoft Power BI in Data Engineering

We have a lot of discussions with clients about a desire to do “better reporting”. They have been using Power BI but feel they now need a data warehouse to…

DevOps Concept Imaginet Canada USA

The Power of DevOps in Business Intelligence

Common pain points experienced when building Business Intelligence (BI) data assets and how Imaginet uses DevOps to mitigate them. If you’re a Business Intelligence developer, have you experienced some of…

Let’s Build Something Amazing Together

From concept to handoff, we’d love to learn more about what you are working on.
Send us a message below or call us at 1-800-989-6022.