You can send an email by th following method you could put this as a
selection change but you would end up with a lot of emails.
If you want to trigger it when a specific cell or range are changed you
could compare each cell in the range on each selection change.
My preference would be to send email as a save event.
Set OutMail = OutApp.CreateItem(0)
On Error Resume Next
With OutMail
.To = "Jimmy Page"
.Subject = "Changes to workbook"
.Body = "Changes have been made to workbook 1"
.Send
End With
On Error GoTo 0
Set OutMail = Nothing