Use an Office 365 email account to send outgoing mail from Loome Publish.

You will need to create an Azure Application Registration with the Microsoft Graph application permission of Mail.Send and provide the Client Id, Tenant Id and Client Secret here.

Pair this with an Application Access Policy to limit what mailboxes can be sent on behalf of with this Client Id -

Enter the Tenant Id of the Azure Ad app registration.
Enter the User Principal Name of the account used to send email.
Enter the Client Id of the Azure Ad app registration.
Enter the Client Secret of the Azure Ad app registration.