How to Apply, Rename, and Remove Flags From Apple Mail Messages

Use flags to personalize your Mail experience

Red warning flag on the beach
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Apple Mail flags are regularly used to mark incoming messages that need further attention. While that may be their primary purpose, Mail flags can do much more. That's because Mail flags aren't just a bit of color attached to emails; they're a form of smart mailboxes and can do many of the things other mailboxes in the Mail app can do, including being used in Mail rules to automate and organize your messages.

Information is this article applies to the Mail application in the following operating systems: macOS Catalina (10.15), macOS Mojave (10.14), macOS High Sierra (10.13), macOS Sierra (10.12), OS X El Capitan (10.11), OS X Yosemite (10.10), OS X Mavericks (10.9), OS X Mountain Lion (10.8), and OS X Lion (10.7).

Mail Flag Colors

Mail flags come in seven colors: red, orange, yellow, green, blue, purple, and gray. You can use any flag color to mark a message type. For example, red flags may indicate emails you need to respond to within 24 hours, while green flags indicate tasks that have been completed.

You can use the colors any way you want, but over time, it can be challenging to remember what each color was intended to mean. You can change the names of the flags as needed.

Assigning Flags to Email Messages

There are three methods of flagging a message:

  1. To flag a message, click once on the message in the Mail app messages list to select it, and then from the Message menu, select Flag. From the pop-up Flag menu, select the flag of your choice.

    Flagging a Mail message on a Mac
  2. The second method is to right-click on a message in the messages list and select a flag color from the pop-up menu. If you hover your cursor over a flag color, its name appears—if you've assigned the color a name.

    Right-click menu for flagging messages in Mail on a Mac
  3. The third way to add a flag is to select an email message and then click on the Flag drop-down button in the Mail toolbar. The drop-down menu displays all available flags, showing both colors and names.

    The Flag drop-down menu in Mail on a Mac

When you use one of these methods to add a flag, the flag icon appears to the left of the email message.

Changing Flag Names

While you're stuck with the colors Apple provides, you can rename each of the seven flags to anything you want to personalize the Mail flags and make them much more useful.

To change a Mail flag's name:

  1. Click the disclosure triangle next to Flagged in Mail's sidebar to reveal all the flag colors.

    The Flagged category in the Mac Mail sidebar
  2. Click once on a flag's name. For example, click on the Red flag, wait a few seconds, and then click on the Red flag once again to highlight the existing color name and allow you to type in a new name. Enter the name of your choice so that you can see at a glance what the flag represents.

    The Mail sidebar showing the Flagged section with name change
  3. Repeat this process with each color to rename all seven Mail flags if you want to use them all.

    The renamed Flag entries in Mac Mail

After you change a flag's name, the new name appears in the sidebar. However, the new name may not be visible yet in all menu and toolbar locations where flags are displayed. To ensure your changes migrate to all locations in Mail, quit Mail, and then relaunch the app.

Flagging Multiple Messages

To flag a group of messages, select the messages and then select Flag from the Message menu. A menu displays the list of flags and their names. Make your selection to assign a flag to multiple messages.

Sorting by Mail Flags

Now that you have various messages flagged, you want to be able to view those messages that were important enough to be coded with a flag color.

Clicking on Flagged in the Mail sidebar displays all the flags. Select a single color flag by expanding the Flagged section. Each flag is a smart folder. Clicking on one of the colored flags displays all the messages that are marked with that flag's color.

Removing Flags

Remove the flag from a message by using any of the methods for adding a flag, but select the option to Clear Flag or—in the case of right-clicking a message—select the X option for the flag type.

For example, to remove the flag from a message, select the message (or messages) and click the Flag button in the Mail toolbar and select Clear Flag from the pop-up menu.

Path to remove a flag in Mac Mail