Outlook, by default, never sends email reminders, just the reminder sound and window. See if you have any third party add-ins for Outlook or perhaps your smartphone that sends an email reminder.

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Milly Staples [MVP - Outlook]
Post all replies to the group to keep the discussion intact. All
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reading.
After furious head scratching, EdG asked:
| I have entries on my calender and reminders set to send 15 minutes
| before each event. That works fine in the typical reminder box 15
| minutes before as I want. BUT, addtionally, for each event, I get an
| email in my Outlook mail that reminds me of the appointment the next
| day. It comes in 24 hours in advance. I want to get rid of that, but
| cannot find the setting. Any help?