Do you have any steps you've tried, and any specific errors you can share? I'm afraid that there isn't enough detail here to help you much more. Though, I'd also recommend using SendGrid or something else. You'll get more reporting, troubleshooting, security, and configuration options.

DNN has the default SMTP options: Anonymous, Basic, NTLM, OAuth

Because of security reasons we have to use Microsoft Graph Api... Upgraded to the latest version of DNN 9.13.4 but I don't see the Microsoft Graph options.

We use the OAUTH option. This uses Microsoft Graph.
In Microsoft Azure, you create an App Registration.
The only permission needed is Microsoft Graph -> STMP.Send (Delegated)

And what do you use for SMTP server in DNN? I keep getting "535: 5.7.3 Authentication unsuccessful [AM0PR02CA0223.eurprd02.prod.outlook.com 2025-01-03T12:59:36.344Z 08DD2AC3E9C1C2B2]"

My app registration has the permission you mention and I am now looking at these settings on the authentication tab of the app registration:

Select the tokens you would like to be issued by the authorization endpoint:
[ ] Access tokens (used for implicit flows)
[ ] ID tokens (used for implicit and hybrid flows)

But no luck so far in various combinations...

Related: https://dnncommunity.org/forums/aft/5331

Hi Stepan,

I hope this will help you:

• In DNN
  • Personabar - Security - More - SSL Settings:
    Make sure that SLL Settings = ON
     
• In Exchange
  • Create a mailbox with a licence.
  • As Admin: In the accountsettings ensure that the option Verified SMTP is enabled
    Userdetails - E-mail - E-mail apps
  • NB: In the tenantsettings Verified SMTP is not always enabled.
    You can enable this option for a user with the Powershell command:
    Set-CASMailbox -Identity [login-address] -SmtpClientAuthenticationDisabled $false
     
• In Azure
  • Create an App registration
    • Redirect URIs:

      • https://[DOMAINNAME]/Providers/SmtpOAuthProviders/ExchangeOnline/Authorize.aspx

      • https://[DOMAINNAME]

    • Secret

    • API Permissions

      • Microsoft Graph

        • Delegated -> SMTP.Send (Send emails from mailboxes using SMTP AUTH)

• In DNN

  • Servers - Seversettings - SMTP Server

    • SMTP Sever and Port = smtp.office365.com:587

    • SMTP Authentication= OAuth

    • Auth Provider = Exchange online

    • Tenant Id = [Directory (tenant) ID] 

    • Client Id = [Application (client) ID]

    • Client Secret = [client secret value]

  • Save Settings

  • Authorize

    • Using the Microsoft Mailbox credentials

  • Test SMTP Settings