If you use Outlook to manage meetings and appointments, calendar reminders are essential — but Outlook’s built-in features can fall short if you’re trying to automate reminders, notify attendees, or send alerts via SMS, email, or Teams.
In this guide, you’ll learn:
What reminder automation options Outlook supports (and what it doesn’t)
Why Outlook’s limitations make it hard to scale
How to use Timelier to automate reminders via email, SMS, and more
Outlook provides basic reminder tools — but they’re designed for individuals, not teams or automation.
You can set one default popup reminder per event.
You can edit a reminder manually for individual events.
You can snooze a popup reminder (with some limits).
All-day events have fixed default reminders:
Classic Outlook: 18 hours before
New Outlook/Web: 5:00 PM the day before
Reminder settings only affect you — not attendees.
Want to see which Outlook versions support which features? Check out our Outlook reminder feature breakdown →
Microsoft now lets you add per-event email reminders — but with major limitations:
What you can do:
Add one or more reminder emails to a calendar event
Choose to send to yourself or all attendees
Include a custom message
What you can’t do:
Set default email reminders for all events
Send to only some attendees (e.g., accepted only)
Send to non-attendees (e.g., assistants or clients)
Automate email reminders based on time, keywords, or rules
Use templates or reusable messages
Need help setting these up? Follow our Outlook reminder setup instructions →
Outlook allows you to flag email messages for follow-up, setting a pop-up reminder for yourself and (optionally) the recipient — but this feature comes with strict limitations.
You can only apply “Follow Up” → “Add Reminder” to regular email messages.
You cannot use it on calendar event invitations — neither sent nor received.
If you want the recipient to also see the reminder flag, your Microsoft 365 tenant must have the “flag for recipients” option enabled.
This setting is controlled by IT administrators and is often disabled by default.
If disabled, the flag will appear only for you, not the recipient.
Bottom line: Follow Up is not a substitute for calendar-based reminders or automated attendee notifications.
If you want to go beyond Outlook’s built-in options, Timelier.com offers full reminder automation — for yourself, your guests, and anyone else you need to notify.
Connect your Outlook calendar
Set up rules that trigger reminders based on:
Event title, attendees, location, or keywords
Send reminders automatically via:
SMS
Microsoft Teams (and more soon)
Choose exactly who gets reminders — e.g., only those who haven’t RSVP’d, or add reminders to non-attendees of the meeting (such as an assistant)
| Feature | Outlook | Timelier.com |
|---|---|---|
| Conditional (rules-based) reminders | | |
| Email reminders | (manual setup per event) | (rules based) |
| SMS/Phone reminders | | |
| Target specific attendees | | |
| Conditional rules | | |
Outlook gives you popup reminders and limited email alerts — but if you need automation, targeting, or delivery across multiple channels, you’ll need more than what Outlook offers.
With Timelier, you can:
Automate reminders based on flexible rules
Send alerts via email, SMS, or Teams
Control exactly who gets notified and when
Ready to take control? Try Timelier.com — connect Outlook and start sending reminders in minutes →
No, unlike Google Calendar, Outlook supports setting only a single reminder on an event. Also, unlike Google Calendar, there is no option for the reminder to be an email rather than a popup.
Classic Outlook does not have this feature. New Outlook and Outlook on the Web allow you to manually schedule reminders on a per-event basis. See section 3 above.
The “Follow Up” feature lets you flag individual emails (not calendar events) for a reminder. However, it is mainly for your own tracking. It does not automatically send a new email, and recipients outside your Microsoft 365 organization typically won’t see the reminder.
Classic Outlook does not have this feature. In New Outlook and Outlook on the Web you could manually schedule multiple reminders for an event. For a more streamlined workflow in which reminders can be automatically scheduled based on user-defined rules, use a service like Timelier.com.
Not usually. Even inside the same Microsoft 365 tenant, whether a recipient sees the reminder depends on their Outlook settings. If the recipient is external (outside your organization), they likely won’t see the flag at all.
The best way is to use a service like Timelier.com. It connects directly to your Outlook calendar and sends automated reminders via email, SMS, phone calls, and more — based on rules you set, without needing manual emails or complicated workflows.
