Outlook not connecting to server and web edition not allowing access

Question

UTC Date: 2026-03-04T15:40:43.667Z
Client Id: E52FE09A97C043649169FCB846058068
Session Id: 553cc32d-975c-4085-9a13-9c92b0821751
Client Version: 20260220002.10
BootResult: configuration
Back Filled Errors: Unhandled Rejection: Error: 500:undefined|undefined:undefined
err: Microsoft.Exchange.Data.Storage.TenantAccessBlockedException
esrc: StartupData
et: ServerError
estack: Error: 500
    at Object.w [as createStatusErrorMessage] (https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.19966414.js:2:10207)
    at https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.19966414.js:2:43093
st: 500
ehk: X-OWA-Error
efe: LO0P265CA0013
ewsver: 15.20.9678.16
emsg: TenantAccessBlockedError

Answer 1

Sorry to hear that you’re having trouble signing in. Please try the options below:

Clear cookies and cache in your browser, then close and reopen the browser and try again.

Try a Private/InPrivate window in Microsoft Edge. If your account has a secondary alias (additional sign-in email/phone), try signing in with that alias instead of the primary one.

Test on a different network (for example, a mobile hotspot). If possible, you can also temporarily use a VPN just to test whether the issue is network-related.

Answer 2

The error Microsoft.Exchange.Data.Storage.TenantAccessBlockedException / TenantAccessBlockedError with HTTP 500 indicates that access to the mailbox tenant is blocked on the server side. In this state, Outlook on the web and Outlook clients cannot successfully connect, and local troubleshooting (reinstalling Outlook, clearing cache, etc.) will not resolve the issue.

Because the block is occurring in the service, resolution requires action on the service side (for example, by the tenant administrator or Microsoft support). The appropriate next steps are:

1. If this is a work or school account (Microsoft 365 / Exchange Online):
   • Have a Microsoft 365 administrator sign in to the Microsoft 365 admin center and check:
     • Service health for Exchange Online.
     • Any alerts or messages indicating that the tenant is blocked or restricted.
   • If the tenant shows as blocked or there are no clear admin-side actions available, the admin should open a support case using the business support channel.
2. If this is a personal Outlook.com account:
   • Sign out of all sessions (for example, using the “Sign out of everywhere” option referenced in similar Outlook.com incident resolutions) and then wait for backend changes to propagate before trying again.
   • If the issue persists, use the consumer support path for Outlook.com to contact support so that the block on the mailbox/tenant can be investigated and removed on the server side.

Local Outlook profile repair, app reinstall, or device changes will not fix a TenantAccessBlockedError because the failure is generated by the Exchange/Outlook.com service itself when attempting to access the mailbox.

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References:

• Fix Outlook connection problems for Microsoft 365 account
• Outlook.com address returning TooManyObjectsOpenedError - Microsoft Q&A