Is there a way to configure it to block emails incoming-or-outgoing so
that
realms A,B and C will only allow relay based off of two conditions: A:
user
SA itself can't do what you want, for one very simple reason: SA is merely a
message filter that adds markup to a message, SA is not a message router of
any sort.
But that isn't to say it can't be done, you just needs some more parts, most
of which you probably already have.
I don't know what tools you are using, nor how your network is set up. If
you give some more info on that there are probably many here that can offer
useful suggestions. I would assume that you simply want to set up your
incoming routings such that mail to the filtered domains comes from the
filter and goes directly into their inbaskets. For the non-filtered
domains, you probably want to install SA essentially into the same part of
the path that you have the 3rd party solution for the other domains.
Outbound filtering is also a matter of how you set your system up.
Loren
