Exchange Connection Problems

Fix Cannot Add Exchange Accounts to iPhone Mail App

Maira Mehtab Sep 22, 2026 869 views

Question details

Users are unable to add Exchange email accounts back into the native Apple Mail application on iPhones, despite the same accounts functioning normally on macOS devices.

Product: Apple Mail / Microsoft Exchange
Device & OS: iOS 18.3.1
Scenario: Setting up or re-adding a Microsoft Exchange email account on an iPhone.
Observed behavior: The addition process fails exclusively on the native iOS Mail app. This issue is officially tracked as Microsoft incident EX1021490.

Before you start

Ensure your iPhone is connected to a stable internet connection and verify that your Microsoft Exchange credentials are correct by logging into your account on a web browser.

Solution 1Recommended

Use Microsoft Outlook for iOS as a Workaround

Since the issue exclusively affects Apple's native iOS Mail app, utilizing the official Microsoft Outlook mobile application allows you to access your Exchange emails immediately.

This service degradation (tracked as EX1021490) is specific to the iOS Mail app's connection with Exchange servers. Microsoft has confirmed that the Outlook for mobile application remains completely unaffected by this bug.

Download the App

Open the App Store on your iPhone, search for 'Microsoft Outlook', and download the application.

Add Account

Launch the Outlook app and tap 'Add Account' on the welcome screen.

Enter Credentials

Input your Exchange email address and password, then follow any multi-factor authentication prompts required by your organization to complete the setup.

Immediate Access: Using Outlook for iOS will restore your access to emails, calendars, and contacts while Apple and Microsoft work on a permanent fix for the native Mail app.

Solution 2

Contact Apple Support to Provide Diagnostic Logs

Apple requires diagnostic logs from affected users to investigate and resolve the native Mail app integration issue in iOS 18.3.1.

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Frequently Asked Questions

Why does my Exchange account work on my Mac but not on my iPhone?

The current synchronization bug (tracked as EX1021490) specifically affects the native Apple Mail app on iOS 18.3.1. The Mail application on macOS uses a different connection framework, which is why it remains unaffected.

Is Microsoft fixing the EX1021490 issue?

Both Microsoft and Apple are aware of the service degradation. Microsoft confirms the issue lies with the native iOS Mail client integration, and Apple is collecting user diagnostic logs to deploy a fix in a future software update.

Can I use Apple Mail with Exchange again after the fix?

Yes. Once Apple releases an iOS patch or a server-side fix is implemented to resolve incident EX1021490, you will be able to add your Exchange account back to the native Apple Mail app normally.

How can I check the status of the EX1021490 incident?

If you are a Microsoft 365 administrator, you can monitor the Service Health Dashboard within the Microsoft 365 admin center for real-time updates on this specific incident.

Outlook & Email Problems