Mail settings using Exchange Online modern authentication

Question

Hello All, it is possible to configure SMTP mail setting using Exchange Online with modern authentication and Azure security defaults enabled? Currently I have setup local IIS SMTP relay connected to O365 without security defaults but I would like to connect to my more secured tenant.

Regards Ivaylo

Comments

Any update on this , as Microsoft deprecated SMTP basic auth on Office 365 , this would really make mailing more secure

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Hello,

That is not correct. According to Microsoft, basic authentication is not disabled for SMTP. For details, see https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/deprecation-of-basic-authentication-exchange-online. However, we keep checking for possible approaches to apply modern authentication for email delivery.

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Yes SMTP Auth is indeed deprecated. It would be great to make it work via Graph API

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Hello Roeland,

Unfortunately, there is currently no possibility to use an Azure AD application with Graph API to send emails. Once Microsoft release an update making this available, we will definitely add corresponding changes to Adaxes. As of now, you can keep using Adaxes to send emails as you did before the deprecation of basic authentication for Exchange Online. It is still working fine and you can see the corresponding statements in the article referenced in the above comment.

Answer 1

Hello Ivaylo,

Unfortunately, there is no such possibility. However, we are considering the feature for future releases of Adaxes.

Comments

Due to the issue with SMTP OAuth 2.0 client credential flow in 365, developers can also send email using Microsoft Graph utilising the Mail.Send Application permission and this endpoint: https://graph.microsoft.com/v1.0/users/[email]/sendMail https://learn.microsoft.com/en-us/graph/api/user-sendmail?view=graph-rest-1.0&tabs=http

For best results, send in MIME format.

Unfortunately, this does mean giving the Adaxes Azure App the Mail.Send Application permission which allows it to impersonate anyone.