stupid question about sendmail

[Wojciech Puchar]

>>
>> To:x at y.pl REJECT
>>
>> doesn't work
>>
>> any idea. thank you
>
> Don't use /etc/mail/access, use /etc/mail/aliases.
>
> E.g.:
>
> x:	/dev/null

x is NOT on my server. it will not work.

all i want is when someone send a mail from my server to x at y.pl (which is 
someone else domain) it will not get there and be blocked or redirected