my older microsoft office for Mac (running on iMac) will no longer allow me to login

Question

I have an older version of Microsoft office for Mac. It is running on my iMac. I can no longer use my password to login to my outlook client. Did microsoft sunset support of this product? How can I get access to my mail again?

Answer 1

Support for legacy Outlook for Mac and older Office for Mac versions is being phased out and modern authentication is now required for many Microsoft accounts. Older Outlook/Office builds and older connection methods may no longer be able to sign in, even with the correct password.

From the available information, there are three main angles to check:

1. Version and server compatibility
   • Legacy Outlook for Mac uses Exchange Web Services (EWS) to connect to Exchange Online. EWS in Exchange Online will be retired on October 1, 2026, and Microsoft is already moving users toward newer Outlook clients and modern auth.
   • Legacy Outlook for Mac will stop working against Exchange Online mailboxes starting October 2026, but it will continue to work with Exchange on‑premises.
   • If the mailbox is in Exchange Online and the client is legacy Outlook for Mac, the sign‑in issues are likely related to these changes and modern authentication requirements.
2. Modern authentication vs. old clients
   • If the account is an Outlook.com/Microsoft 365 account, older Outlook/Office clients that do not support modern authentication can no longer sync using the old methods. In those cases, Microsoft recommends upgrading to a newer Outlook client that supports modern authentication.
   • Outlook apps that support modern authentication are available for free from the Mac App Store. After installing the new Outlook, add the email account and it will be configured with modern authentication and sync properly.
3. Options to regain access to mail
   • Install the latest Outlook for Mac that is supported on the version of macOS in use (for example, via the Mac App Store or via a Microsoft 365 subscription download) and sign in there. This uses modern authentication and is the supported path going forward.
   • If the subscription is active, it can be used to activate the most recent Office for Mac version that runs on the current macOS. After installing that version, run Help > Check for Updates once to get the final supported build.
   • If the mailbox is hosted on an older on‑premises Exchange Server that still supports legacy connections, verify the Exchange version with the mail provider and confirm that account credentials and server name are correct in Outlook for Mac (Tools > Accounts > select the account and review settings).

If the goal is simply to get back into the mailbox, the most reliable approach is to move to the current Outlook for Mac (or another modern Outlook app) and sign in there, since older clients and protocols are being retired and may no longer be able to authenticate.

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References:

• End of support for legacy Outlook for Mac
• Modern Authentication Methods now needed to continue syncing Outlook Email in non-Microsoft email apps
• Office running on OS 12.7.6 - Microsoft Q&A
• I can't connect to my Exchange account in Outlook for Mac