You may have trouble quickly spotting new messages in a crowded inbox. Outlook’s conditional formatting feature lets you change the appearance of emails based on rules you set. This article explains how to create a rule to make unread emails stand out with custom colors and fonts.
You can apply these changes to any mail folder view. The formatting is client-side and does not affect how others see your messages.
Key Takeaways: Customize Unread Email Appearance
- View > View Settings > Conditional Formatting: Opens the master list of rules for the current folder where you can add and manage formatting.
- Unread Messages rule: The default rule that controls the look of all unread items, which you can modify directly.
- Font button: Lets you change the text color, style, and size for emails that match your conditional formatting rule.
What Outlook Conditional Formatting Does
Conditional formatting in Outlook is a set of visual rules applied to items in list views, like your Inbox. It changes how emails look based on their properties, such as being unread, from a specific sender, or marked with a certain category.
The formatting only affects your view within the Outlook client. It is not a server-side rule and does not alter the actual email data. You must set it up separately for each mail folder if you want consistent rules across different folders, like your Inbox and Sent Items.
Prerequisites for Using Conditional Formatting
You need a mailbox set up in Outlook for Windows. The feature is available in Outlook as part of Microsoft 365 and Outlook 2021, 2019, and 2016. You must have permission to modify the view of the folder. Conditional formatting works in all standard view types, such as Compact, Single, or Preview.
Steps to Create a Custom Rule for Unread Emails
The most direct method is to modify the built-in Unread Messages rule. This rule already targets all emails with the Unread status, so you only need to change its visual style.
- Navigate to your Inbox
Open Outlook and click on your Inbox folder in the folder pane. - Open the View Settings dialog
Go to the View tab on the ribbon. Click the View Settings button in the Current View group. - Access Conditional Formatting
In the Advanced View Settings dialog box, click the Conditional Formatting button near the bottom. - Select the Unread Messages rule
In the Conditional Formatting dialog, you will see a list of rules. Click on Unread Messages to select it. - Modify the font style
Click the Font button below the rule list. A standard Font dialog will open. Choose your preferred font, style, size, and color. For example, select a bold style and a bright blue color. Click OK to close the Font dialog. - Apply and close the dialogs
Click OK in the Conditional Formatting dialog. Click OK again in the Advanced View Settings dialog. Your unread emails in the current folder will now display with the new formatting.
Creating a New Rule from Scratch
If you prefer a separate rule instead of modifying the default one, you can create a new rule. This is useful if you want to format only some unread emails, like those from your manager.
- Open Conditional Formatting
Follow steps 1 to 3 from the previous method to open the Conditional Formatting dialog. - Add a new rule
Click the Add button. A new rule named Untitled will appear in the list. Type a descriptive name for it, such as Important Unread. - Set the condition
Click the Condition button. In the Filter dialog, go to the Advanced tab. Click the Field button, point to Frequently-used fields, and click on Unread. Set the Condition to Yes. You can add other criteria here, like From containing a specific email address. Click OK. - Choose the font
Click the Font button and select your desired formatting, then click OK. - Finalize the rule
Click OK in all open dialogs to apply the new rule to your folder view.
Common Mistakes and Limitations to Avoid
Formatting Not Applying to New Emails
If newly arrived emails do not show your custom formatting, check the rule’s condition. Ensure the rule is at the top of the list in the Conditional Formatting dialog, as rules are evaluated in order. Also, verify you selected the correct folder view; rules are per-folder.
Rule Disappears After Switching Views
Conditional formatting rules are tied to a specific view of a folder. If you change from the Messages view to the Unread Messages view, your custom rule may not be present. You must reconfigure the rule for each distinct view you use regularly.
Too Many Rules Causing Slow Performance
Applying more than ten complex conditional formatting rules to a folder with thousands of items can slow down scrolling and rendering. Keep your rule set simple and use the Stop Processing More Rules option in custom conditions if you have overlapping criteria.
Conditional Formatting vs. Categories and Flags
| Item | Conditional Formatting | Categories and Flags |
|---|---|---|
| Primary Use | Automatic visual sorting based on email properties | Manual organization and follow-up tracking |
| Visibility | Only visible in your own Outlook client view | Can be synced to the server and seen on other devices |
| Persistence | Tied to a specific folder view; can be reset | Stored with the email item itself |
| Automation | Rules-based; applies instantly to matching items | Requires manual application or inbox rules |
| Best For | Quick visual scanning and priority identification | Structured filing, project grouping, and task management |
You can now make unread emails instantly recognizable with your chosen colors and fonts. Try creating a second rule to highlight emails from your key contacts in a different color. For advanced control, use the Filter dialog in the rule condition to combine criteria, such as formatting unread emails that are also marked as high importance.