What Does Flagging an Email Do? Purpose and Benefits

EmailLaiba Siddiqui • Published: May 16, 2025 • Updated: June 09, 2025 • 6 minutes READ

I used to overlook the flag email feature until I missed an important message. It had been buried under newsletters and spam traps (honest regrets!). And I missed it because going through all the email clutter felt soul-draining. But I am not alone; 67% of people feel stressed by their inboxes, just like me.

That’s when I realized how helpful that small flag icon is. It may look unnecessary initially, but it organizes our inbox so nothing important slips through. Today, I’ll walk you through what flagging an email does and how flagged emails work in different clients.

What is a Flagged Email?

A flagged email is any message you mark with a flag option to remind yourself to follow up or take action later. We usually do this to prioritize important emails in our inbox.

If you coordinate with multiple people at work, you probably have long email threads. And if a task is mentioned in a specific conversation, you may forget it because it gets buried under so many regular emails. To avoid this, you can flag (or star) those messages. This way, you won’t miss out on any critical tasks.

Most email apps even group flagged emails into a separate section, so they’re easier to find when we need them.

How to Flag Emails in Popular Email Clients

Now, let’s see how to flag an email on different clients.

Flagging Emails in Gmail

Gmail doesn’t have the flag option, but a ⭐ option that works the same way. It automatically filters starred emails into a separate Starred folder, where you can find messages later. If you’re using Gmail with the Priority Inbox, starred emails can even affect how your inbox is sorted, so the most important messages stay at the top.

Here’s how you can do it:

1. Click the star icon next to the sender’s name in your inbox.

2. You can also open the email and click the star at the top.

3. Now, go to the Starred folder from the left corner of your Gmail. It will show you all the starred messages.

You can even customize your stars. Here’s how:

1. Click the settings icon in the top right corner, then select See all settings.

2. In the General section, press Ctrl + F and type stars in the search bar that appears. This will highlight where our desired star option would be. So scroll down to find this option.

3. Then, you can drag your preferred start color or even a different symbol from the Not in use part to the In use part.

4. Save changes in the end and that’s it. You will now have your chosen star colors.

Flagging Emails in Outlook

Outlook has the Flag option. Our flagged emails sync directly with Tasks. Because every time we flag an email, it’s automatically added to our To-Do list in the Tasks pane and Microsoft To Do.

This way, we can manage any important tasks or updates assigned through emails. You can even set deadlines, reminders, and track follow-ups through the flag marker.

Here’s how you can do it:

1. Hover over the email you want to flag in your inbox.

2. Click the flag icon that appears on the right side of the message. It will turn red when you click on it.

3. To set a reminder, right-click the flag and choose a follow-up time, such as today, tomorrow, or any custom time that works best for you.

4. Once your work is done, select the Mark Complete option. The flag will turn into a checkmark ✔️.

Flagging Emails in Apple Mail

Like Gmail, which lets us customize stars, Apple Mail allows us to flag emails using different colors. I use the red flag for urgent messages and the blue for personal notes. But you can do it however you like because Apple doesn’t have any specific meanings for these colors.
Here’s how you can do it:

On iPhones or iPads:

1. Open the Mail app.

2. Press and hold or swipe left on the email you want to flag.

3. Choose the Flag option. You can also go to More and choose from different colors to customize your flags.

4. Now go to Mailboxes > Edit. From here, check the Flagged option.

5. Now you will have a separate Flagged category where you can find flagged emails.

On Mac:

1. Open the Mail app and select the message you want to flag.

2. Click the flag button on the Mail toolbar.

3. Orange is the default colour. But you can change this to your desired colour from the available list.

Why Should You Flag Emails

Here’s why you should flag your emails:

• Our verification emails or important messages may get buried under newsletters or promotional emails. Flagging keeps those messages visible.
• Flagged emails on some platforms, like Outlook, appear in our task list. So instead of searching inboxes later, we’ve a reminder to follow up.
• If you’re like me (I forget things more often than I’d like to admit), flagging is the best way to stay on top of things without remembering everything.
• Our inbox stays organized, and we get peace of mind knowing nothing important will slip through.

Different Types of Flagged Emails

There are no strict rules on what type of email we should flag because the choice depends on us and the email client we use. But here are some general categories which you can use to classify flagged emails:

• Follow-up flags: Remind you to take action later, such as replying to a message or completing a task.
• Priority flags: Mark urgent or time-sensitive emails.
• Categorical flags (color-coded): Organize emails by type. For example, red for urgent, blue for personal, and yellow for pending (that’s what I use).
• Custom flags (Outlook): Allow you to set start dates or due dates, and task reminders.
• Starred emails (Gmail): Work like flags to mark important messages for easy access.

Best Practices for Using Email Flags

Now that you know the primary purpose of flags and how to use them, here are some best practices to make the most out of them:

• Create a flagging system in which different colors or star/symbol types have different meanings. This will reduce mental clutter because you can recognize a prioritized email at a glance.
• Regularly review flagged emails so they don’t pile up like the rest of our inbox. That way, you won’t miss any message that needs follow-up or action.
• Combine flags with other features, such as labels in Gmail, folders in Outlook, or rules in Apple Mail, to create a more organized inbox.

Wrapping Up: Organize Your Inbox With Email Flags

You’re not alone if you ever find yourself scrolling endlessly only to find that one important email. But I have a simple fix for you.

Flags (or stars, depending on the app) are an easy way to keep track of important messages. No matter what you’re using — Gmail, Outlook, Apple Mail, or another app — most have a flagging feature.

So, follow the steps I shared above, and you’ll be able to quickly mark and find the emails that need your attention without any inbox chaos.

FAQs

What Happens When You Flag an Email?

When you flag an email, it’s marked as important and moved to a separate folder named Flagged or Starred.

How do I Use Flags with Labels in Gmail?

In Gmail, you can use stars as flags and apply labels to group emails by category. For example, if you star an email for follow-up and label it “Client Work”, you can track its priority and context.

What Does Flag Mean in Email?

Flags are visual cues for emails that need more attention or a second look. Similar to sticky notes, they signal that the message should be revisited.