Const DigitalSigCtrl =  719 
Const EncryptMsgCtrl =  718 

Dim myItem As Outlook.MailItem
Dim myInspector As Outlook.Inspector
Dim oDigSignCtl As CommandBarControl
Dim oEncryptMsg As CommandBarControl
Dim oCBs As CommandBar

Set myItem = Outlook.CreateItem(olMailItem)
myItem.To = "xxx@mydomain.com"
myItem.Subject = "Subject"
myItem.Body = "Body message"
Set myInspector = myItem.GetInspector
myInspector.Display
Set oCBs = myInspector.CommandBars( 6 )
Set oDigSignCtl = oCBs.FindControl(msoControlButton, DigitalSigCtrl, "", True)
Set oEncryptMsg = oCBs.FindControl(msoControlButton, EncryptMsgCtrl, "", True)

oDigSignCtl.Execute
oEncryptMsg.Execute
myItem.Send
End Sub