banned content DISCARD istead of BOUNCE

[Damian]

> I have one problem, the $final_banned_destiny is D_BOUNCE but i'd like
> totally DISCARD some extension (exe|com|scr) without notification to
> sender and recipient.Is it possible?
You can suppress sender notification but not recipient and admin
notification via:
> [ qr'.\.(exe|com|scr)$'i => 'DISCARD']

In order to suppress all notifications one would have to write code,
unfortunately.