The end is near (for legacy auth)!

Microsoft announced first the deprecation of Basic Authentication for Exchange Online and EWS protocol starting Oct. 13, 2020 here.

Note: At this time this affected ONLY the protocol EWS for mailboxes on Exchange Online!

Later it was announced that this also happens for other protocols like Exchange Active Sync (EAS), POP, IMAP and PowerShell at the same time here, in order to improve security.

Looking at the protocols, you might wonder about REST. This was announced for REST API v1.0 shortly after the announcement for EWS here and highlighted again here.

With this, there is no doubt that Basic Authentication is dead for Exchange Online and Microsoft Graph and every vendor should look into alternatives for authentication AND also update their products. There are still way too many products without support of Modern Auth.

The deprecation of Basic Authentication raises a few questions:

  • How can I access mailboxes with my service account?
  • My application needs access to all or only a subset of calendars. How can I securely configure this?
  • I need to Send-As or Send-on-Behalf of recipients’ e-mail addresses. What do I have to configure?

In this post I’m trying to cover some scenarios and try to explain advantages and disadvantages.

Note: This article is ONLY covering OAuth and Exchange Online! I assume you’re using a Bearer token for authentication in your request!

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