Add an "encryption" option 'use_transport' which does not bother with
encryption and just relies on transport security.
For admins this makes sense as none of the admin messages is really
confidential.
This is also a valid option for a subscriber and makes some sense in
scenarios where the mail provider manages the subscriber key (sic!)
and does server side decryption. Think twice before using this.
Requested-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Reviewed-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
