Question about blocking Mail (fwd)

[Marcel Blenkers]

Sorry,

again wrong recipient ;) should update my adress-book..

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Hi there,

i have one Question regarding blocking mails.
But not from the outside, but from the inside.

Here is the Problem:

Let´s suppose we do habe a sender xy at yx.com and an recipient (outside) 
with qw at wq.com

I would like to block mails from the internal Sender xy to the outside 
recipient qw. And i would like to block mails from inside sender yx with 
subject "something".

As sender xy does first of all a lot of unnecessary mails with subject 
something to the outside world, just to test if the mail-server is 
working. Which is a pain in the ass. And it does create traffic.

Also this person does send mails to another person, who does not want to 
receive no longer mails from this user, but the recipient is the only 
person who does not want to receive those mails.

So my question:

Is there any kind of ruleset to accomplish these kind of things?

Like:

From:	yx at xy.com	To: qw at wq.com 	warn

And the sender yx should receive a mail that this mail got blocked, due to 
the wishes from recipient qw.


Any ideas?

Thanks for any kind of help

Greetings

Marcel