I am currently writing an essay about securing E-Mails. Now I'm at the point where I want to know if it´s possible to force STARTTLS in connections via SMTP or POP3/IMAP from the clients' side. I know I can configure the client so it uses STARTTLS but I don't know if I can force it.
Background of this idea will be that no downgrade attack will be possible without noticing.
Does anyone know if there is such an implementation in circulation for Outlook (Or other mail agents)?
