Outlook GetInspector(). , , , :
library(RDCOMClient)
olMailItem = 0
OutApp <- COMCreate("Outlook.Application")
outMail <- OutApp$CreateItem(olMailItem)
outMail$GetInspector()
signature = outMail[["HTMLBody"]]
outMail[["Recipients"]]$Add("dest@dest.com")
outMail[["Subject"]] = "some subject"
outMail[["HTMLBody"]] = paste0('<p>some body', signature, '</p>')
outMail$Display()
outMail <- NULL
OutApp <- NULL