Outlook 365 authentication failed. 3 Authentication.

Outlook 365 authentication failed. com no longer accepts. Troubleshooting these issues is technical and it might help to have some background in how OAuth works. It appears your authenticator (broker app) did not complete the authentication process. I'll circle back with time if possible. May 21, 2015 · When adding an Exchange Online Plan 1 (Office 365) account I always get a “The server was found, but authentication failed. May 12, 2023 · Hi Team, I installed postfix on Kali Linux and configured office365 account (username and password). Steps I have done: I Apr 18, 2022 · "User is authenticated but not connected" when trying to use ThunderBird as mail client access office365 after confirmed below: Ensure that the user name and password are correct and that the same user name and password run properly on… May 28, 2025 · Hi everyone Our AVDs are currently running on Windows 10 22H2 (Build 19045. 3 Authentication unsuccessful [BN6PR14CA0013. Aug 11, 2025 · The Office 365 email admin needs to enable SMTP AUTH on your Office 365 email account. 3. office365. I can tell you that this mailbox does exist in 365 as I have it added to both my Outlook for Windows client and I can add it to OWA, so that also answers the permissions Jun 6, 2023 · I want to send emails via smtp with an oauth2 token. 5. 0 for IMAP and SMTP in the Exchange Online has been announced. This only happens with a Microsoft365 P1 license. Feb 27, 2024 · Last Updated: February 27, 2024 Issue Users signing into Outlook. prod. Jun 25, 2025 · After you enable modern authentication for Outlook in Exchange Online in a Microsoft 365 tenant, Microsoft Outlook can't connect to a mailbox if the user's primary Windows account is a Microsoft 365 account that doesn't match the account they use to sign in to the mailbox. This issue arises because SMTP authentication is blocked by default in Microsoft 365 settings for enhanced security. com to microsoft. namprd14. My phantom email address showed up when I reinstalled outlook and again failed authentication. Sometimes, the entry box might not appear if the app is locked. Oct 22, 2024 · As of this week, modern auth on the Outlook mobile app (on iOS and Android) is no longer authenticating with modern authentication to an Exchange 2019 server which is configured with hybrid modern authentication. CANPRD01. May 4, 2020 · Recently the support for OAuth 2. 0 is a secure but complicated authentication pattern. Dec 30, 2024 · As far as I know, it is possible to use the Microsoft Entra SP as credentials for smtp. com -all I have found from the one of the email headers that the message was sent from this ip address:… May 12, 2025 · If Outlook for Windows fails to authenticate with the Office365 POP3 email server with error 0x800CCC92, reading below to fix the problem. This was previously configured and has… Jun 4, 2025 · OAuth 2. The connection to your mail server timed out error in Outlook for iOS or Outlook for Android - Exchange Hello everyone, I'm trying to assist my manager with some technical difficulties regarding his Outlook account. Reply reply bjohnrini •• Edited Horizon 2306 vCenter 7. The question authentication-failed-because-the-remote-party-has. Sep 8, 2025 · In this troubleshooting guide I’ll explain why Microsoft has changed its authentication protocols for Outlook. com successfully. Nov 28, 2022 · Summary Microsoft is discontinuing basic authentication for Microsoft 365 customers definitively. I also deleted all the accounts related to MS off my Android phone. This stopped working Friday. [YT2PR01CA0024. You could have a look. For business Office 365 accounts, using Exchange might be more stable than IMAP because Exchange natively integrates with Outlook for Mac. Jun 30, 2025 · I have a two users that logs into their laptops with their Work Office 365 credentials. 22544099 Windows 10 22H2 DEM and FSLogix (Office containers only Aug 8, 2025 · Learn how to troubleshoot and fix common Office 365 (Microsoft 365) SPF and DKIM email authentication failures, ensuring your emails reach the inbox and improve deliverability. Oct 4, 2024 · Anyone else run into their notifications failing as of Oct 1, 2024? Authorization failed (535 5. Jan 15, 2025 · Describes how to troubleshoot authentication issues that may arise for federated users in Microsoft Entra ID or Office 365. com 2024-01-04T04:11:11. Oct 14, 2022 · Can't connect to Outlook with POP/IMAP and Modern authentication - Exchange Describes why you can't connect to Outlook by using POP/IMAP and Simple Mail Transfer Protocol (SMTP) protocols, and Modern authentication. Check for Multi-Factor Authentication (MFA): If Multi-Factor Authentication is enabled for the account, you may need to generate an App Password to use for SMTP authentication instead of the regular account password. Is the IMAP disabled completely by the office365? Jan 31, 2024 · You receive the Authentication failed error when trying to sign in to Microsoft Flow. 7. If your domain offers both IMAP and Exchange connectivity, try setting it up as an Exchange account: Oct 20, 2025 · Provides troubleshooting steps for errors that you encounter when trying to sign in to Microsoft Teams. Automate email actions in Power Automate with SharePoint as the data source, including sending emails, capturing metadata, and saving email content to SharePoint. ” blocks access to email accounts in Outlook and other Microsoft 365 apps, even after pressing Reload or re-adding the account. This is Microsoft's decision, and it is entirely beyond our control. I followed the common pattern to activate OAuth2 for accessing mails via IMAP. May 4, 2025 · To fix the Microsoft 365 authentication or initialization failed error, follow these solutions: Verify your internet connection Check your account credentials May 4, 2025 · Authentication or initialization errors within Microsoft 365 applications, notably seen with Outlook on Windows 11 and Windows 10, represent a frequent and often disruptive challenge for both everyday users and IT professionals alike. 3 Authentication unsuccessful It . The mailbox shows "Disconnected" in the status bar. I’ve got no idea where my email address is being picked up. Sep 1, 2018 · I am an Office 365 Business and Personal subscriber. In the event Mar 10, 2023 · I have a custom Microsoft 365 business email domain and an email account of myemail@secretdomain. [SY6PR01CA0083. 6 days ago · Please refer to this guide for detailed instructions: How to Fix Microsoft 365 Authentication and Initialization Errors in Outlook on Windows | Windows F… Please note that although I suggest reviewing the steps in the link above, please ensure you verify each instruction before applying it to your system for security and compliance purposes. User using MacBook and iPhone devices sign out automatically with "Authentication failed due to flow token expired " Jun 5, 2025 · A cloud-based service included in Microsoft 365, delivering scalable messaging and collaboration features with simplified management and automatic updates. You may not have the right permissions to add this mailbox or this mailbox doesn’t exist’. The third-party application uses SMTP submission to authenticate Office 365 accounts. Possibly this setting needs to be re-activated (turn off and on again) to enable. COM 2024-10-04T16:53:39. 10000 or higher) when connecting directly as Outlook. Until a few weeks ago, my Outlook for Windows used to work fine in all my three PCs. The authentication issue occurs when Outlook is trying to connect to Teams to retrieve your free/busy status, but you don't have a Teams license. Launch Terminal on your Mac by doing either of the Oct 20, 2022 · Hi there, I created a new O365 account and I am using the default email address to test this. In these cases, you need to set up Internet Information Services (IIS) Topic Replies Views Activity I am getting problem with scan to email feather in Sharp MX M264N Dec 16, 2024 · Outlook for Android will not authenticate when adding my account on a new Pixel phone - msg 'error during authentication, please try later' May 7, 2024 · Office 365 smtp OAUTH2 granting access token but when i try to send email get the error 535: 5. Mar 27, 2025 · Provide guidelines on how to prevent authentication error codes 80070520, -2147023584, or 2147943712 when you sign in to Microsoft 365 apps. On office 365 sides, I just created test1user and after that on test1user Go -> Manage email apps --> Authenticated SMTP= enabled Go-->… Feb 2, 2025 · office 365 "Cannot connect to SMTP server" "SSL negotiation failed" Matthew Brady 210 Feb 2, 2025, 2:59 PM Jul 4, 2024 · Authentication unsuccessful, user is locked by your organization's security defaults policy. Jun 28, 2025 · However, users sometimes encounter Microsoft Authenticator Error 500121, which blocks access to essential Microsoft 365 apps like Outlook, Teams, and SharePoint. 3 Authentication Jun 25, 2025 · Additional resources Training Module Configure client connectivity to Microsoft 365 - Training This module examines how clients connect to Microsoft 365. com, port 993). The app will request a new login from the user. This authentication gap means that the tool may try to connect to credentials with basic authentication, which can result in failure even if connection tests show no network issues. 5854) For some time now, our users have been experiencing issues signing in to certain Office 365 applications, especially OneDrive and Outlook. Oct 18, 2024 · A cloud-based service included in Microsoft 365, delivering scalable messaging and collaboration features with simplified management and automatic updates. ca. 3 22357613 ESXi 7. Emails Not Being Delivered2. But I always get the following error message: "Authentication unsuccessful". He says that he can't log into Outlook Nov 20, 2023 · I can read email from my personal Outlook account using the above piece of code but cannot read from office365 mail. com] , code: 535" When I try… Mar 31, 2023 · For client credentials flow, you need to add application permissions under Office 365 Exchange Online Make sure to grant admin consent for all the application permissions. Apr 18, 2023 · It could be that the SMTP authentication of your Office 365 account hasn't been enabled. Dec 13, 2021 · It's possible to log in to the device with another account, but receive the "Device authentication failed" when using a different user. May 16, 2025 · Why can’t you authenticate your Microsoft account? Read this guide to fix Microsoft 365 authentication or initialization failed. The Sign-in log in Office 365 shows the failure reason as “Device authentication failed“ This is a pure online Office 365 environment. If using Two-Factor Authentication, generate an App password in Office 365 and use it instead of your regular password to authenticate with IMAP. You just switch to OAUTH2 based authentication in the near future. 538Z 08DCE450F51FB4BD]) I guess basic auth for SMTP is done now from Mi Admins can learn how email authentication (SPF, DKIM, DMARC) works and how Microsoft 365 uses traditional email authentication and composite email authentication to allow and block spoofed messages. 0 authorization code flow Specification Feb 27, 2025 · Use OAuth authentication for high volume emails for Microsoft 365 Learn how to use OAuth authentication to connect with SMTP protocols and to access email data for Office 365 users. Check the email address and password” a) Username and Password ARE correct b) I have tried adding it as an exchange account instead of Auto-Discovery c) This works in Outlook as expected with the same credentials d) is this meant to work in the Free Edition? e) there Apr 9, 2025 · General issues Check status of the feature and Authentication Agents Ensure that the Pass-through Authentication feature is still Enabled on your tenant and the status of Authentication Agents shows Active, and not Inactive. 139 Authentication unsuccessful, the request did not meet the criteria to be authenticated successfully. This comprehensive guide explains what error 500121 means, why it happens, and provides step-by-step instructions on how to fix Microsoft Authenticator error 500121. , Microsoft Edge) without the correct single sign-on flow triggered can lead to partial logins and errors within the new Outlook app. Authentication Conflicts Being simultaneously signed into a Microsoft account in your browser (e. Feb 27, 2023 · A cloud-based service included in Microsoft 365, delivering scalable messaging and collaboration features with simplified management and automatic updates. Jul 19, 2022 · I am facing an authentication failure issue while trying to connect for both IMAP and POP3 protocols using the Client Credential Grant flow for Nov 21, 2024 · AUTHENTICATE failed. Feb 19, 2020 · After I activated the 'Default Security' in Office 365, the multifunctionals can't scan-to-mail . This guide will help you troubleshoot common problems, ensuring a smooth integration of Postfix with Office 365. AuthenticationFailedException: 535 5. User trying to access Application: Windows Sign In Sign-in error code: 50155 Failure reason: Device authentication failed. For many years, applications have used Jun 25, 2025 · Describes why you can't connect to Outlook by using POP/IMAP and Simple Mail Transfer Protocol (SMTP) protocols, and Modern authentication. Note: This content can help you with your work or school account. Sep 11, 2025 · Fixes an issue that federated users on iOS devices can't use Certificate-Based Authentication (CBA) to authenticate. We recommend using Modern Authentication when connecting with our service. com through Basic authentication may experience recurring password prompts in Outlook and other third-party email applications. Sep 11, 2023 · DEBUG SMTP: AUTH LOGIN failed LoginServiceImpl : validateUserId :SSHRException :org. If you're using POP/IMAP and SMTP for an Exchange Online account in Outlook, you must enable Basic authentication for these protocols (until it's permanently deprecated in October 1). Windows 10 21h2 LTSC. Authentication did not complete If you received an "Authentication did not complete" message it could be for one of the following reasons: App is locked: Make sure Microsoft Authenticator is unlocked on your device. Expected - auth codes, refresh tokens, and sessions expire over time or are revoked by the user or an admin. Contact your administrator. Jul 19, 2022 · Yes, Microsoft is disabling password based authentication, and it may have been disabled in the server you’re using. Learn more about OAuth 2. Oct 4, 2024 · This is typically done in the email account settings on the Office 365 admin portal. Aug 6, 2020 · Office 365 Unable to Authenticate Your Credentials is an error that occurs if your username uses an incorrect format. Using the Python code below I am not able to send an email to another user due to an SMTP Jan 3, 2024 · Contact your administrator. outlook. You can resolve problems with Microsoft Authenticator by checking the tips in this article and reviewing some of the known errors. mail. Jun 10, 2024 · Outlook supports Modern Authentication in all current Microsoft 365 subscription SKUs and Outlook 2021 LTSC (any SKU with build 11601. Second user, just exchange… Jan 18, 2023 · Sinds 18/01/2023 we experience the following troubles with some user: Outlook, teams, onedrive was unable to authenticate Creating a new profile in Outlook failed autodiscover Outlook didn't show a pop-up for authentication but kept the profile… Mar 14, 2025 · Solves the authentication error that occurs when you try to use the Dynamics 365 App for Outlook in the Outlook desktop client. Specifically, this issue rears its head when users log in via web browsers like Google Chrome and Microsoft Edge (yes, even Microsoft's own browser isn't spared). Suddenly, all three PCs stopped working a few weeks ago,… Jun 25, 2025 · Troubleshoots issues with migrating a mailbox from an on-premises or third-party IMAP system to Exchange Online. 0: Microsoft identity platform and OAuth 2. Sep 11, 2025 · Describes how to troubleshoot single sign-on (SSO) user account issues in Microsoft 365, Azure, or Microsoft Intune. PROD. com, Hotmail. May 13, 2024 · Set up SPF identify valid email sources for your Microsoft 365 domain - Microsoft Defender for Office 365 | Microsoft Learn Please understand that our initial response may not always resolve the issue immediately. Quit Outlook. May 12, 2025 · Detailed instructions to fix the following problem: Outlook Authentication with Office 365 fails (Office desktop apps Sign in to Office 365 failed). MailAuthenticationException: Authentication failed; nested exception is javax. Tip 3: If you use User Codes or any other form of authentication, make sure the option "Use Name as Sender" is disabled in each entry of the address book. Fix it with this guide. Office has the latest version with new teams. Our Setup: We're using imaplib in Python to connect to the Outlook IMAP server (outlook. Oct 24, 2022 · Use OAuth authentication for high volume emails for Microsoft 365 Learn how to use OAuth authentication to connect with SMTP protocols and to access email data for Office 365 users. Many customers report OAuth issues with their custom connectors because their services aren't implementing it correctly. For Microsoft 365 SMTP, you can also use an Entra application with a service body for authentication. However, you may encounter some issues during this process. Next step… see if there is anything in my 365 Admin panel that is gumming things up. Authentication Oct 11, 2024 · When I try to add a shared mailbox that I full delegate access to, I get the message ‘Authentication failed that didn’t work. Feb 27, 2024 · Solves the authentication error that occurs when you try to use the Dynamics 365 App for Outlook in the Outlook desktop client. I use it as an email client against out corporate server. It also provides instruction on how to configure name resolution and Outlook clients, and how to troubleshoot client connectivity. Jul 29, 2025 · Guidance about how to troubleshoot problems with single sign-on (SSO) in Office Add-ins, and handle special conditions or errors. For more information about how to enable Modern Authentication, see the following articles: Enable Modern Authentication in Microsoft 365 Configure on-premises Exchange to use Hybrid Modern Authentication Jun 25, 2025 · Fix issues with printers, scanners, and line of business applications that use Microsoft 365 or Office 365 to send email. Click Reload to try again. I will only give the following common suggestions for mobile authentication errors from the perspective Jan 23, 2025 · Microsoft recently acknowledged authentication snafus with the Authenticator app for those trying to sign in to Microsoft 365 services like Word, Excel, and Outlook. The affected AVD host then needs to be restarted for the sign-in to Outlook and OneDrive to work again. We have taken actions to protect our customers and mitigate their risk to the increase in bad actors trying to gain access to their accounts. Connection Refused or Timeout Errors3. If you're having problems verification codes on a personal Microsoft account, see Troubleshooting verification code issues. 954Z 08DC0C18648A6980] 2024-01-04 04:11:11 SMTP ERROR: Password command failed: 535 5. Mar 14, 2025 · Even with 2FA enabled and a valid application password set, the migration tool may still rely on the basic authentication method that Outlook. I am able to retrieve a token (using scope… Nov 22, 2021 · Outbound TLS authentication failed with error RevocationOffline for Send connector Outbound to Office 365. ausprd01. Aug 27, 2025 · The message “Authentication or initialization failed. Mar 10, 2025 · Tip 2: Enable "Authenticated SMTP" for the Office 365 account in the Microsoft 365 Admin Center. You can check this in the Office 365 Exchange admin center. This is a known issue. The office suite is baked into the image. I use 2309 with Dem, appvol and fslogix (office containers only). Describes how to troubleshoot single sign-on implementation in Office 365, Azure, or Microsoft Intune. The applica For more information, see How do I report a suspicious email or file to Microsoft?. Oct 27, 2024 · Introduction In Part 2, we successfully configured Postfix to relay emails through Office 365. com. html is the same as your problem. Jan 26, 2022 · How to configure IIS for relay with Office 365 When you set up a multifunction device or application to send email through Office 365, there are some cases where the device or application can't connect directly to Office 365. As you setup Seamless SSO, check whether any conditional access policy applied for session control. Mar 3, 2025 · It causes when Authentication failed due to flow token expired. Ensure that the IMAP setting in your Office 365 account is enabled. Provides a comprehensive list of symptoms and their solutions. For more information, see the article: Use the Microsoft 365 admin center to enable or disable SMTP AUTH on specific mailboxes. Troubleshoot user issues for Microsoft Intune app protection policies - Intune Oct 11, 2021 · Follow 25,306 Reputation points Oct 26, 2021, 7:39 PM @tuyen1644 , based on my test, the code you provided is correct, I can use it to send the email from hotmail. For many users, the sign-in gets stuck in an endless loop. 3, 22348816 VMware Tools 12. com, similar to how it is used in Azure Communication Services. I get error SmtpCmdResp: 535 5. Since other ActiveSync clients are working fine, the problem may be on the Outlook side and how it handles authentication properties during migration. For this reason, you can no longer use MailStore software with Microsoft 365 / Exchange Online via basic authentication, and will need to switch to modern authentication, which our software has supported since Version 13. May 12, 2025 · Changes to OAuth authentication for Microsoft 365 (formerly Office 365, abbreviated as O365) business and academic hosted email accounts and services. To allow the SMTP auth, you can refer to the following instruction. Feb 5, 2025 · There is no plan for Outlook clients to support OAuth for POP and IMAP, but Outlook can connect use MAPI/HTTP (Windows clients) and EWS (Outlook for Mac). Oct 21, 2020 · Hi When I try to connect to Office365 SMTP server, I get this error: Server returned error: "334 VXNlcm5hbWU6 334 UGFzc3dvcmQ6 535 5. IntroductionCommon Issues and Solutions1. However, with your help and more detailed information, we can work together to find a solution. protection. Jan 17, 2025 · Hi, @Evandro Boa Semedo The issue appears to be related to how specific accounts are authenticated in the Outlook mobile app after migration. Jun 5, 2023 · Hello, I'm trying to use Phpmailer on a web host, that use the SMTP from Office365 And i get an error SERVER -> CLIENT: 535 5. Enable or disable authenticated client SMTP submission (SMTP AUTH) in Exchange Online. 0 votes Report a concern Mar 15, 2025 · Can someone please define where this policy is located? how can i exclude a user. You can check status by going to the Microsoft Entra Connect blade on the Microsoft Entra admin center. Troubleshoot issues with high volume email for Microsoft 365 Learn how to troubleshoot issues with high volume email for Microsoft Jun 6, 2025 · I deleted Office apps and reinstalled. Does the user licence have an impact? The first user has full MS365 licence. 0. Jun 13, 2025 · Microsoft is investigating an ongoing incident that is causing users to experience errors with some Microsoft 365 authentication features. com, and Microsoft 365 email accounts and how to fix these basic authentication errors. Resolution To fix this issue, follow the below steps to execute a Terminal command. g. springframework. 139 Authentication unsuccessful, user is locked by your organization's security defaults policy. Learn how to reinstall packages for ADAL and Live ID to troubleshoot authentication issues and Outlook issues that may go into the Need Password state. Dec 18, 2022 · As of now, the problem is fixed by turning on SMTP Authentication in Admin panel > Settings > Org Settings > Modern Authentication > check "Authenticated SMTP (Used by ‎POP‎ and ‎IMAP‎ clients to send email messages)" with the help of Microsoft assistant. Following the guide I've set up the application permissions and IMAP and SMTP connection. 139 Authentication unsuccessful, basic authentication is disabled. Jun 25, 2025 · Resolves an issue in which an Outlook client can't connect to Exchange Online when Autodiscover points to on-premises Exchange Server. Please complete the login process in the Authenticator, Company Portal, or primary MS app on your device. Feb 18, 2021 · Hello, SPF authentication fails for our outbound emails sent by Exchange Online despite having this DNS record v=spf1 include:spf. 3 Authentication unsuccessful Jun 25, 2025 · Resolution To configure certificate authentication in Outlook 2016 and later versions, we recommend that you use Modern Authentication. Feb 1, 2024 · Also try to authenticate your device or application directly with a Microsoft 365 or Office 365 mailbox, and send mail using SMTP AUTH client submission This option isn't compatible with Microsoft Security Defaults. Old credentials, profiles, or registry entries sometimes cause authentication loops or misconfigurations. The TLS authentication mechanism is DomainValidation. OUTLOOK. When admins or users submit items to Microsoft for analysis, we do the following checks: Email authentication check (email messages only): Whether the message passed or failed email authentication checks: SPF, DKIM, DMARC, and composite authentication. sdzdb bqnkzo j2km9s0 ey3g 8ov v131i kc2dp rb8 uokqx emx62nn