Discussion - way of ensuring items are sent encrypted to specific recipients?

Ideally you’d be able to say:

  1. always send encrypted to people for whom I hold certs
  2. always send encrypted to this subset of those people

There is apparently no way of doing this in Outlook 2010-13.

Send rules in Outlook are too limited, you cannot even run a script.

Outlook macro would do it I guess, but I have no time to program. Hints here, but the code examples need a way to read a list from disk:

Also at very bottom of same ref, amongst email-send-guard software, the Janus software would appear to be helpful, but availability situation seems strange. Others cost ££.

There are some services which may do it, but as with all services you are v. dependent and they cost:

There are also a few non-service plugins, but none which seem to do it - read near bottom of this link:

Comodo secure email supported it but is discontinued

Any ideas using free software guys?