Most logins to Microsoft Office 365 Exchange require direct authentication to NetID Login. However, some clients/protocols use basic authentication. With basic authentication (also called proxy authentication), the email client transmits the username and password to Office 365, and Office 365 forwards the provided credentials to NetID Login. This article answers general questions about Basic Authentication.
With basic authentication, your email/calendar client will transmit your username and password to Office 365 (Exchange Online). Office 365 will forward your credentials to the NetID Login Service. The NetID Login Service will verify the credentials and return a token to Office 365. If authentication was successful and the user is authorized, the email/calendar client will be connected to Office 365.
If your email/calendar client uses modern authentication, your credentials are not sent to Office 365 (Exchange Online). Instead, you'll be redirected to the familiar NetID Login screen. If your account is protected by Duo MFA, you will be required to confirm your login. Your client may maintain a connection to Office 365 with an OAuth token, so you may not be required to use NetID Login each time you use the client.
The following is a non-exhaustive list of clients which are capable of authenticating to Office 365 Exchange Online with modern authentication:
Basic authentication in Office 365 is less secure for multiple reasons:
Microsoft has already discontinued support for basic authentication with Outlook REST API. Microsoft has announced an end of support for basic authentication with EWS, EAS, POP, IMAP, Remote PowerShell (RPS) on 10/13/2020. Support for basic authentication with Office 365 SMTP is expected to continue beyond 2020.
New Microsoft update: September 2021: We're making some changes to improve the security of your tenant. We announced in 2019 we would be retiring Basic Authentication for legacy protocols, and in early 2021 we announced we would begin to retire Basic Authentication for protocols not being used in tenants, but not disable Basic Authentication for any in-use protocols until further notice. Today, we are announcing that we are restarting the program to end the use of Basic Auth in Exchange Online. Beginning October 1, 2022, we will begin to disable Basic Auth in all tenants, regardless of usage.
The full announcement can be found at https://techcommunity.microsoft.com/t5/exchange-team-blog/basic-authentication-and-exchange-online-september-2021-update/ba-p/2772210
To manage this feature, please review the Office 365 - Manage Password Security article.
Office 365 team will enable Password Security on Oct. 4, 2021.
Important: This will only affect users who have configured their email@example.com account within an email client which currently is not configured to use Modern Authentication. After Oct 4, 2021, to access your email, you will need to use an email application which supports Modern Authentication. See the reconfigure section below for client options available to you after Oct 4, 2021.
Beginning in November 2021, DoIT will begin the final phase of upgrading university email accounts to modern authentication. This final group is limited to service accounts, some of which are tied to crucial university business processes. During this phase of the project, we ask that departments proactively identify service accounts that currently use basic authentication so that we can share the time and bandwidth to assist you and reduce interruptions in service.
Important: This will only affect users who have configured their service account (firstname.lastname@example.org) within an email client which currently is not configured to use Modern Authentication. See the reconfigure section below for guidance on how to reconfigure your client to use Modern Authentication.
If you are using Basic authentication to connect to your email account, you may be suspect to any of the following: unauthorized access, use of your NetID credentials for credential stuffing, brute force, and password spray cyberattacks.
To protect your account and NetID credential, it is highly recommended that you make sure Password Security is enabled on your account - to manage this feature, please review the Office 365 - Manage Password Security article.
To begin using modern authentication through exchange, open a desktop or mobile email client, remove your UW Madison email address, and then re-add your UW Madison email address. When authenticating the account, you should receive a pop up or be redirected to UW Madison's secure login portal, which is the only time you should enter your password.
Information regarding how to configure specific mail clients can be found in:
Microsoft supports authentication to O365 with "legacy" protocols: IMAP, POP, and SMTP. Any client that supports OAuth 2.0 should be able to authenticate to Office 365. Support for OAuth 2.0 with O365 is dependent upon the client developer. The UW-Madison Office 365 team has no control over client support. Configuration instructions will be unique for each client, but you can refer to the Thunderbird IMAP/SMTP modern authentication configuration instructions found here: Office 365 (Thunderbird) - Configure Modern Authentication
If you'd like to learn more about basic and modern authentication in Office 365, please review the following documents: