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

Microsoft Outlook includes a built-in reminder system that works across emails, calendar events, and tasks. Whether you're using the desktop app, the web version, or the mobile app, the process differs slightly — and understanding those differences helps you choose the right approach for how you actually work.

What Outlook Reminders Actually Do

A reminder in Outlook is an alert that pops up at a scheduled time to prompt you about something — a meeting, a deadline, a follow-up email. It's separate from a notification. Notifications are passive; reminders demand acknowledgment. When a reminder fires, a dialog box appears and stays there until you dismiss it or snooze it.

Outlook reminders are tied to one of three item types:

• Calendar events — meetings, appointments, recurring blocks
• Tasks and To-Do items — action items with due dates
• Emails — flagged messages that trigger a follow-up alert

Each works a little differently under the hood.

How to Add a Reminder to a Calendar Event

This is the most straightforward use case. When you create or edit a calendar event in Outlook:

1. Open Calendar and create a new event (or open an existing one)
2. Look for the Reminder dropdown — in the desktop app it appears in the ribbon or the event form itself
3. Select your preferred lead time: 0 minutes, 5 minutes, 15 minutes, 1 hour, 1 day, and so on
4. Save the event

The reminder fires at the specified interval before the event start time. For recurring events, the reminder applies to every instance unless you edit individual occurrences.

In Outlook on the Web (OWA): The reminder dropdown appears in the event editor under the time fields. The available options are similar, though the interface is cleaner and browser-based.

In Outlook Mobile (iOS/Android): Tap an event, select Edit, and look for the alert/reminder field. Mobile versions often offer fewer granular options than the desktop app.

How to Add a Reminder to an Email 🔔

Emails don't have reminders by default — you add them through the Follow Up flagging system.

In Outlook Desktop:

1. Right-click the email in your inbox
2. Select Follow Up
3. Choose Add Reminder
4. Set a start date, due date, and specific time
5. You can also add a custom note in the reminder text field
6. Click OK

The email gets a flag icon, and a reminder alert fires at your set time. This is particularly useful for emails that need action but that you can't handle immediately.

Quick flag vs. full reminder: A single left-click on the flag icon in your inbox applies a default "Today" flag with no time-specific reminder. For an actual timed alert, you need to go through the right-click → Follow Up → Add Reminder path.

In Outlook on the Web: Right-click the email, select Flag, then look for the option to set a reminder date. The interface varies slightly depending on whether you're on the classic or updated OWA experience.

How to Add a Reminder to a Task

Outlook Tasks (and the integrated Microsoft To Do experience in newer versions) support reminders natively.

1. Open the Tasks section or To Do panel
2. Create a new task or open an existing one
3. Look for Reminder in the task detail pane
4. Toggle it on and set a specific date and time
5. Save the task

In versions of Outlook integrated with Microsoft To Do, the task reminder syncs across devices — so a reminder set on desktop will also appear on your phone if you're signed into the same Microsoft account.

Variables That Affect How Reminders Behave

Not all Outlook setups work identically. Several factors shape the experience:

The last point catches a lot of people off guard. Outlook desktop reminders are not system-wide alerts — they depend on the application being active. If Outlook is closed when a reminder is scheduled to fire, it won't appear until you reopen the app.

Default Reminder Settings

Outlook lets you set default reminders so you don't have to configure each event manually:

• Go to File → Options → Calendar
• Check Default reminders and set your preferred lead time
• This applies to all new calendar events you create going forward

A similar default exists for tasks under File → Options → Tasks.

The Difference Between Reminders and Recurring Alerts

A reminder fires once at a set time. If you need something more persistent — like a weekly check-in prompt — a recurring calendar event with its own reminder is a better tool than a single flagged email. The two features are complementary, not interchangeable.

For team-based deadlines, reminders set inside shared calendar events only notify the organizer and attendees who have accepted — not everyone in an organization. And whether attendees see a reminder depends on their own Outlook settings, not just yours.

How far in advance you need alerts, whether you work across multiple devices, and whether your account is Exchange-based or consumer-grade — these are the details that determine which reminder method actually fits into your workflow. ⏰