Phishing messages to your work email can be costly if the wrong person replies with confidential information. If you use Outlook for your email client, it can help identify those messages from outside senders to make sure they stand out. Having some context before opening a message will help prevent falling for the phishing scheme when you know it is coming from an outside source. In Outlook 2013 and 2016, you can configure the Inbox’s View to color code emails from outsiders. If you mostly deal with internal emails, this will make those phishing emails stand out.
In Outlook, with the Inbox folder selected, click on the View tab in the Ribbon. Then click the ‘View Settings’ button with two gears.
Next click on the ‘Conditional Formatting…’ button (User defined fonts on each message).
Click the ‘Add’ button to create a new rule and give it a name like ‘FromOutsiders’ or ‘External Senders’, etc.
Next click the ‘Font…’ button and choose a different font than the default font. I went with Century Gothic in red so it is quite obvious when an external email comes in.
Next, click on the ‘Condition…’ button.
In the field to the right of the ‘From’ button, type a single @ (at sign) and click OK.
This will pick up any email coming from an outside source and change the font of the subject line that appears in the message list. The normal font of the email in the reading pane will not be affected by this.
With another rule and filter, you could even create another condition with @yourdomain.tld in the ‘From’ field to highlight spoofed emails.
I recommend implementing this feature and thinking about other ways the Outlook View conditional formatting can benefit you. I have been using it for a couple of months now with no problems. The only false positive has been “missed conversation” emails from Skype for Business. Any emails from outside the company simply have a different font and color for the subject and from field in the Outlook message list. This may only work for email accounts with an Exchange back-end, I have not tried it with any other setups.