iPhone 17 repeatedly sending multiple meeting invitations to Microsoft 365 attendees

hi,I am currently using an iPhone 17 running iOS 26.3. I use the native iOS Mail and Calendar apps connected to a Microsoft 365 (Exchange) account for my professional workflow.

The Problem:

Whenever I create a new meeting or update an existing one, the attendees receive the invitation 4 to 5 times repeatedly. This is causing significant confusion and unprofessional clutter for my colleagues.

Technical Details:

• Device: iPhone 17

• OS Version: iOS 26.3

• Account Type: Microsoft 365 / Exchange Online

• Apps Used: Native Apple Mail & Calendar

[Re-Titled by Moderator]

Original Title: Cleander reaptly

iPhone 17

Posted on Feb 21, 2026 6:32 AM

Top-ranking reply

KiltedTim

Level 10

234,380 points

Posted on Feb 21, 2026 7:04 AM

This is a bug in Exchange ActiveSync. You may have also experienced a bug where events created on the iPhone apparently correct in the native calendar, but are set up in the wrong time zone (Iceland) when viewed in Outlook online or on a computer.

The solution here is to stop using the native calendar on the phone and use the Microsoft Outlook app from the App Store instead.

If you want to see a unified calendar that includes both your work calendar and personal calendars from iCloud, etc. you can leave it set up but avoid creating, or modifying Exchange calendar entries in the native calendar app.

I manage a MS365 tenant with hundreds of users. This problem is not uncommon. We strongly recommend using the Outlook app instead of the native apps on iOS.

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iPhone 17 repeatedly sending multiple meeting invitations to Microsoft 365 attendees

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