Exception in check_sender_access?

[Patric Falinder]

Hi,

In my config I have done so that every mail with a NULL sender gets 
checked at ips.backscatterer.org like this:

smtpd_restriction_classes = backscatter_rbl
backscatter_rbl = reject_rbl_client ips.backscatterer.org

smtpd_recipient_restrictions =
.....
check_sender_access hash:/etc/postfix/check_backscatterer


/etc/postfix/check_backscatterer:
<> backscatter_rbl


However, is it possible to make an exception for a recipient in some way?
If a mail with a NULL sender comes in to except...@domain.com it won't 
check the senders IP at ips.backscatterer.org?

I'm using Postifx 2.7.1


Thanks,
-Patric