What Next?
Microsoft has officially ended support for Basic Authentication, a long standing login method used across Microsoft 365 services. This change is part of a broader effort to strengthen security and reduce the risk of cyberattacks. Organizations that rely on Microsoft Exchange Online must now prepare for a more secure future using Modern Authentication.
Understanding what this change means, who it affects, and how to prepare is essential for maintaining access and protecting business data.
Microsoft’s Decision to End Basic Authentication
Microsoft first announced in September 2019 that it planned to stop supporting Basic Authentication across its APIs. The goal was to improve security by eliminating authentication methods that rely only on usernames and passwords.
The original timeline pointed to 2021, but Microsoft delayed enforcement due to the global impact of COVID 19. A final date was later confirmed. Beginning October 1, 2022, Microsoft started disabling Basic Authentication for all Exchange Online tenants in Microsoft 365.
The only exception to this change is SMTP Auth, which remains available in limited scenarios. At the same time, Microsoft enabled OAuth 2.0 across its APIs, moving customers to an industry standard authorization framework.
What This Change Means for Microsoft 365 Users
Basic Authentication allows access to a mailbox using only a username and password. While simple, this method offers little protection against modern cyber threats.
Existing organizations using Exchange Online were given additional time to transition. New Microsoft 365 tenants now have Basic Authentication disabled by default. Microsoft may also disable it automatically if it detects that it is not actively in use.
Organizations running Exchange Server on premises or in hybrid environments are not immediately affected. However, those still using Basic Authentication may experience issues with tools like Remote PowerShell once the protocol is no longer supported.
Why Microsoft Is Disabling Basic Authentication
The main reason for this change is security. Basic Authentication is highly vulnerable to brute force and password spray attacks. These attacks rely on testing common passwords across many accounts until access is gained.
Because Basic Authentication requires credentials to be stored by apps and services, attackers only need to steal them once. Microsoft considers this protocol outdated and unsafe for today’s threat landscape.
According to the Microsoft Exchange team, keeping Basic Authentication enabled increases the daily risk to organizational data. Microsoft strongly urges users to move all applications to more secure authentication methods.
The Risks of Basic Authentication
Basic Authentication has been widely used for years because it is easy to configure. Users simply log in with a username and password, which is often stored within the application or device.
This convenience comes with a price. If credentials are weak or reused, attackers can exploit them quickly. Password spray attacks are especially effective because many users still rely on simple passwords.
Once attackers gain access to a single account, they can move through the environment, access sensitive data, and disrupt operations.
Moving to Modern Authentication
With Basic Authentication disabled, organizations must adopt Modern Authentication to continue using Microsoft 365 services.
Modern Authentication, also known as OAuth 2.0, is not just a single protocol. It is a framework that uses secure tokens instead of stored credentials to access cloud resources.
Users still verify their identity with a username and password, but applications receive time limited access tokens instead of login details. These tokens define exactly what access is allowed and can be revoked at any time.
This approach reduces risk and improves visibility and control.
Security Benefits of Modern Authentication
Modern Authentication prevents apps and services from storing user credentials. Tokens expire automatically and have strict access scopes, which limits potential damage if they are compromised.
It also supports multi factor authentication, adding an extra verification step such as a phone prompt or security key. This significantly reduces the success rate of common attacks.
Together, these features offer stronger protection for Microsoft 365 environments.
Clients and Protocols Affected
Microsoft maintains a list of supported clients that work with Modern Authentication. Common supported clients include:
- Mail app for iOS 11.3.1 and higher
- Outlook on iOS and Android
- Outlook 2013 and newer
- Outlook 2016 for Mac and higher
Administrators should review the Microsoft 365 admin portal for announcements related to their tenant. In some cases, Basic Authentication may already be disabled.
Several protocols are affected by this change, including POP3, IMAP4, ActiveSync, Exchange Web Services, Remote PowerShell, RPC, MAPI, and the Office Address Book. SMTP Auth is the only limited exception.
Basic Authentication vs Modern Authentication
Basic Authentication sends login credentials with every request. Those credentials are stored and reused, creating ongoing exposure.
Modern Authentication uses token based access and requires user approval before apps can connect. Access is temporary, controlled, and more secure by design.
While the transition may require effort, it is a necessary step toward improved cybersecurity.
Final Thoughts
Microsoft has made it clear that Basic Authentication has reached the end of its life. Any app or service that still depends on it will stop working once the protocol is fully disabled.
Preparation is critical. Organizations need to identify affected systems, update applications, and enable Modern Authentication to avoid disruption.
If navigating these changes feels overwhelming, expert guidance can make the process easier. At Realized Solutions, we help businesses adapt to Microsoft security changes and modern IT requirements.
Contact RSI today to ensure your Microsoft 365 environment stays secure, compliant, and fully functional.