Exim filter not working with email forward

[SmokSky]

I have server mail with forward to a yahoo email, but I wan't send email forward if email have header from domain is "@yahoo.com".

Begin i try will block all email forwarder to email "[email protected]" but it filter not working, Emails still forwarder to email "[email protected]",

My Filter:

if $header_to: contains "[email protected]"
then
fail text "Your message to inform email users about the problem..."
finish
endif
if not first_delivery
then
finish
endif

Please help me ! Thanks

 

[Infopro]

Check to see if these similar threads, with same filter, are of use:
Blocking all cPanel users from emailing specific domains/email accounts
Easiest way to block all outgoing mail to a domain