Outlook App on Mac and Iphone

Question

I recently migrated my tenant to another domain, however when I try to setup the email on the Outlook app for my mac and iphone it keep going back to the old tenant, I try removing and reinstalling the app but it is not working, on the Mac I delteted the cache but it is still going back to the old adresss any other options to force this to be deteled

Answer 1

Dear Jorge Sanchez,

Thank you for sharing your issue.

Based on your description, you have migrated your tenant to a new domain. However, your iPhone and Mac devices are still signing in using the old domain. This continues to occur even after reinstalling the applications and clearing cache on macOS.

This behavior may occur because Microsoft identity services can retain cached authentication tokens or Autodiscover records that still reference the previous tenant environment, even if the application itself has been reinstalled.

Please note that, as this is a user-to-user support forum, moderators do not have access to your tenant configuration or internal environment. Additionally, my ability to test on macOS is limited. That said, I will do my best to assist you based on available documentation and guidance.

As a first step, you may try the following:

1/ Clear Keychain Access (remove cached identity tokens)

Close all Office applications

Open Keychain Access (Cmd + Space > type “Keychain”)

Search for: Microsoft, Office, ADAL, and OneAuth

Delete all related entries

This removes stored authentication tokens that may still be linked to the old tenant.

Restart your Mac

For more details, you can refer to: Delete a keychain in Keychain Access on Mac

Please note that the link provided above is not an official Microsoft source. It is shared for reference purposes only to help guide you through the troubleshooting steps. Please review the content carefully and use your own discretion when following any instructions.

2/ Remove and add your new account in Outlook

Open Outlook

Go to Outlook > Preferences

Select Accounts

Choose the affected account

Click the minus (-) button and select Sign Out

Restart your Mac

To re-add:

Follow the same steps, then navigate to Accounts and click the plus (+) button or select Add Email Account. Enter your email address and password

3/ Use Microsoft Office License Removal Tool (if issue persists)

If the device still appears linked to the old tenant, you may use the official Microsoft Office License Removal Tool.

This tool removes all licensing and identity data from your Mac (without uninstalling Office apps). After running it, you will need to sign in again to all Office applications.

For iPhone (iOS), this issue may occur because iOS uses a shared identity system across Microsoft apps (such as Authenticator, Teams, OneDrive), which can reuse cached tokens.

Try the following steps:

1/ Remove account from Microsoft Authenticator

Open Microsoft Authenticator

Locate the old account

Delete it

Go to Settings (in Authenticator) > Device Registration

If your device is registered with the old tenant, unregister it

2/ Reset account state using Microsoft Edge (recommended)

Delete Microsoft apps (Outlook, Teams, etc.) from your device

Download Microsoft Edge from the App Store

Open Edge and navigate to: edge://signin-internals

Tap “RemoveAllAccounts”

You should see a confirmation message

Close Edge

Reinstall the apps (Outlook, Teams, etc.)

Try signing in again

I hope this helps. If anything is unclear or you need further assistance, please feel free to comment.

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Answer 2

On Mac (Outlook for Mac):

1. Fully remove the old account profile
   • In Outlook, go to Tools > Accounts.
   • Select the old/incorrect account in the left pane and remove it.
2. Reset the Outlook account cache/profile
   • Still in Tools > Accounts, select the affected account (if it still shows).
   • At the bottom left, click the three dots (…) and choose Reset Account.
   • This forces Outlook to clear the cached connection and re-sync with the server under the new tenant/domain.
   • Ensure the Mac is connected to the server while doing this.
3. If needed, clear folder cache
   • In the folder list, Ctrl+click or right‑click the problematic Exchange folder.
   • Select Properties > General tab > Empty Cache.
   • Outlook will re-download items from the server using the current tenant configuration.
4. Re-add the account
   • After reset/removal, add the mailbox again using the new domain/tenant sign‑in details.

On iPhone (Outlook / Apple Mail):

If using Apple Mail or another app that keeps redirecting to the old tenant, the old auth/session data must be removed so modern authentication can re‑negotiate against the new tenant.

1. Remove the account from the mail app
   • Go to Settings > Mail > Accounts.
   • Tap the Outlook/Microsoft 365 account and Delete Account.
2. Clear Safari auth/session data (used by the Microsoft sign‑in page)
   • Go to Settings > Safari.
   • Tap Clear History and Website Data.
3. Reboot the iPhone
   • Power off and restart the device.
4. Add the account back using the correct service
   • Go to Settings > Mail > Accounts > Add Account.
   • Choose Outlook.com (or the appropriate Microsoft 365/Exchange option) so OAuth/modern authentication is used.
   • Sign in with the new tenant/domain credentials.

If using the Outlook mobile app, remove the account from within the app, then re-add it after step 2–3 above so the sign‑in flow is forced to the new tenant.

These steps clear cached account data and authentication sessions on both Mac and iPhone so Outlook and Mail stop reusing the old tenant configuration and instead negotiate a fresh connection to the new tenant/domain.

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References:

• Clear the cache in Outlook for Mac
• Outlook and other apps are unable to connect to Outlook.com when using Basic authentication
• Modern Authentication Methods now needed to continue syncing Outlook Email in non-Microsoft email apps