I am testing if deferred delivery time works and see that these emails are not sent. I see nothing in the outbox. Emails do get sent if i just .Send and comment out .DeferredDeliveryTime. Also, I've tried manually changing Do not deliver before time in Outlook and that does work. So I am not sure what is going wrong here with the VBA.
Option Explicit
Private Sub CommandButton1_Click()
Dim olApp As Outlook.Application
Dim olMail As Outlook.MailItem
Dim olAccount As Outlook.Account
Set olApp = New Outlook.Application
Set olMail = olApp.CreateItem(olMailItem)
With olMail
.To = "my email"
.Subject = "test"
.Body = "test"
' .Send
.DeferredDeliveryTime = DateAdd("n", 10, Now)
End With
End Sub