How to Create a Reminder in Outlook: Emails, Calendar Events, and Tasks

Microsoft Outlook has one of the most flexible reminder systems of any productivity app — but that flexibility also means there are several different ways to set a reminder depending on what you're trying to remember and where you're working. Whether you're flagging an email to follow up on later, adding an alert to a calendar event, or setting a task deadline, the process differs slightly in each case.

Here's a clear breakdown of how reminders work across Outlook's main features.

Setting a Reminder on a Calendar Event

This is the most common use case. When you create or edit a calendar event in Outlook, a reminder dropdown appears in the event editor — typically defaulting to 15 minutes before the event.

To set or change a reminder on a calendar event:

1. Open Outlook and go to the Calendar view
2. Double-click an existing event, or click New Event to create one
3. In the event window, look for the Reminder dropdown (usually in the ribbon at the top or within the event form itself)
4. Select your preferred lead time — options typically range from 0 minutes to 2 weeks before the event
5. Save and close the event

The reminder will fire as a pop-up notification at the time you specified. If you're using Outlook on the web (Outlook.com or Microsoft 365 via browser), the same field exists in the event editor — look for a bell icon or a field labeled "Remind me."

Adding a Reminder to an Email 📧

Outlook lets you attach a follow-up reminder directly to an email message — useful when you receive something you need to act on later but can't respond immediately.

To flag an email with a reminder:

1. Right-click the email in your inbox
2. Select Follow Up
3. Choose Add Reminder from the submenu
4. In the dialog box that appears, set a due date and a reminder date/time
5. Click OK

The email will appear flagged in your inbox, and Outlook will pop up a reminder at the time you set. You can also access this through the Home tab in the ribbon — click Follow Up while an email is selected, then choose Add Reminder.

In Outlook on the web, right-click any email and look for the Flag option. More granular reminder times are generally available in the desktop version of Outlook (part of Microsoft 365 or older standalone installs) than in the web client.

Creating a Reminder via Tasks (Microsoft To Do Integration)

For reminders that aren't tied to a specific email or calendar event — just a general task or to-do — Outlook integrates with Microsoft To Do, which handles task-based reminders.

To create a task reminder:

1. In Outlook desktop, navigate to the Tasks section (the checkmark icon in the left sidebar)
2. Click New Task
3. Add a title, then set a Reminder date and time using the fields in the task editor
4. Save the task

Alternatively, flagging an email also creates a task entry in Microsoft To Do, which syncs across devices if you're signed into the same Microsoft account.

Reminder Options: Desktop vs. Web vs. Mobile

The experience varies meaningfully depending on which version of Outlook you're using:

Desktop Outlook gives you the most precise control — including custom reminder times, multiple reminders per event, and full task integration. The web version covers the essentials but strips some advanced options. Mobile is the most limited, primarily surfacing reminders set elsewhere rather than offering the full creation toolkit.

Adjusting Default Reminder Settings

If you find yourself constantly changing the default 15-minute reminder for calendar events, you can update the global default:

1. Go to File → Options → Calendar
2. Under the Calendar options section, check the Default reminders box
3. Set your preferred default time
4. Click OK

This only applies to the desktop version. On the web or mobile, defaults are managed differently or not user-adjustable at the same level.

What Affects How Reminders Behave

A few factors shape how well Outlook reminders work in practice:

• Account type: Reminders on Exchange/Microsoft 365 accounts sync across devices reliably. Personal IMAP or POP accounts may not carry reminders between platforms
• Notifications settings: Outlook reminders depend on the app being open (or running in the background) and your OS notification permissions being enabled
• Sync frequency: On mobile, reminder delivery can lag if the app isn't set to sync frequently
• Calendar permissions: For shared calendars, reminder settings apply to the viewer's own copy of the event — not the event creator's 🗓️

When the Same Reminder Method Doesn't Work for Everyone

Someone using Outlook primarily for personal email on a single device has a very different experience than someone on a corporate Microsoft 365 environment where reminders sync across a phone, laptop, and Teams. A freelancer managing their own calendar may get full value from task-based reminders in To Do, while an enterprise user might rely entirely on calendar event alerts tied to meeting invites.

The version of Outlook you have access to, how your account is configured, and which devices you use most will all shape which reminder method fits your workflow best — and whether reminders behave exactly as you'd expect them to.