For those wanting to eliminate the SMTP AUTH protocol from their PowerShell scripts, Microsoft has three ways to send email using Graph APIs (raw Graph APIs and the Send-MgUserMessage and Send-MgUserMail cmdlets from the Microsoft Graph PowerShell SDK. This article looks at how to use the Send-MgUserMail cmdlet and explains why the SDK really does need two cmdlets to send messages via Exchange Online.
https://practical365.com/send-email-powershell-graph/
