The current version of Delegate365 v9.7 comes with some improvements. See the details here.
SMTP Authentication in Users / Mailbox settings: A new switch SMTP Authentication has been added to the Mailbox settings of a User. This allows, see Enable or disable authenticated client SMTP submission (SMTP AUTH) in Exchange Online. Usually, Microsoft recommends to disable SMTP AUTH in your Exchange Online organization and to enable it only for the accounts (mailboxes) that still require it. If security defaults is enabled in your organization, SMTP AUTH is already disabled in Exchange Online. However, admins can modify this setting in the Mailbox features section. The SMTP Authentication dropdown allows to set the setting to* On, Off, *and Organization settings. which means that the settings for the user are inherited from the organization´s transportation rules settings.
This setting corresponds to the setting in the Microsoft 365 Admin Center, under Users / Active Users / Select a user / Manage Email Apps / Authenticated SMTP switch or with PowerShell. In PowerShell, this setting is set with Set-TransportConfig and Set-CASMailbox with an attribute named SmtpClientAuthenticationDisabled, where the organization settings are equal to $null, On means $false, and Off means $true. This is simplified in Delegate365 to be more understandable.
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