Postfix restriction problem

[gianni21]

Hi i'm giovanni, i've a mailserver with postfix (relase 2001) and i've added an alias all@domain.it that point to all the mailbox of my domain, so now i've a big problem, this alias is shooted by spammers and i want to restrict the policy and allow to use it only if the sender is logged on my domain. Well, i've find this official tutorial:
/etc/postfix/main.cf:
smtpd_recipient_restrictions =
check_recipient_access hash:/etc/postfix/access

/etc/postfix/access:
all@my.domain permit_mynetworks,reject
all@my.hostname permit_mynetworks,reject
--------
so i've applied it to my config. files:

/etc/postfix/main.cf:
smtpd_recipient_restrictions =

check_recipient_access hash:/etc/postfix/access

/etc/postfix/access:
all@domain.it permit_mynetworks,reject
------
so at the end i've given these command:
postmap /etc/postfix/access
postfix reload

The result isn't good, when any mail client try to send an email the mail client software give a timeout and it's impossible to reach the addressee.
When i clean up the access file and main.cf all returns like before...(the clients can send email and everyone can send email at all@domain.it)
maybe with this modify i've cancelled part of default configuration and therefore it doesn't work ?
Thanks a lot