signs me out when I'm trying to sign in

Hi Ashleigh Michele Falasca, 

Welcome to Microsoft Q&A Forum! Have a good day and I hope you're doing well! 
Thanks for reaching out. I understand how frustrating it can be when sign‑in completes but you’re immediately signed out afterward, especially after entering a verification code. I appreciate you sharing the details. 

To help narrow this down and better understand where the issue might be occurring, could we please start with the following checks? 

1. Confirm Outlook for Mac is fully up to date 

First, let’s make sure Outlook is running on the latest available version, as sign‑in behavior and authentication fixes are frequently included in updates. 

Please sign in to any Office app on your Mac (for example, Word or Excel), then go to: 
Help > Check for Updates and install any available updates. 

You can also compare your installed version with the latest releases listed here: Update history for Office for Mac – Office release notes (Microsoft Learn) 

Keeping Outlook fully updated helps rule out any known sign‑in issues that may have already been addressed. 

2. Check whether your account can sign in via Outlook on the web 

Next, could you please try signing in to your account using a web browser at: https://outlook.office.com 

• If you’re able to sign in successfully on the web and your mailbox loads normally, this suggests your account and verification process are working as expected. 
• If the web sign‑in also signs you out immediately after verification, the behavior may be related to account or sign‑in policies rather than the Outlook app itself. 

This step helps determine whether the issue is client‑specific or account‑related. 

3. Try reverting to Legacy Outlook on your Mac 

If web access works normally, the next step would be to verify whether the behavior is isolated to New Outlook for Mac. Please try switching back to the legacy experience: 

• Open Outlook 
• Select Outlook > Revert to Legacy Outlook 
• Then sign in again using your school account 

This comparison helps confirm whether the issue occurs in both versions of Outlook or only in the New Outlook experience. 

I hope these steps help clarify the situation at least partially. Once you’ve had a chance to try them, I’d really appreciate it if you could share the results. That will give us more insight and allow us to suggest more targeted troubleshooting steps. 

If I’ve misunderstood anything or if any part of the explanation is unclear, please feel free to reach out anytime. 

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".    

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.  

If you are being signed out immediately after attempting to sign in on your Mac, it could be due to a few reasons. One common issue is related to the account type you are using. Ensure that you are signing in with a "Work or School" account that is associated with a Microsoft Entra Directory or Office 365 tenant. If you are using a different account type, that may cause the sign-in issue.

Additionally, if you are already signed in with another account from the same organization, this can also lead to sign-out problems. In such cases, you may need to use the Keychain Access app to delete any existing password entries related to Office, which can help resolve the conflict.

To delete the entries:

1. Open the Keychain Access app.
2. Search for "Office".
3. Delete any entries found.
4. Try signing in again after exiting the Keychain Access app.

If these steps do not resolve the issue, consider reaching out to your IT department for further assistance.