Iam using postfix,courier IMAP, LDAP with squirrel mail in MAIL SERVER.
I have blocked attachment through MailScanner to internet and set to 10 MB for intranet.
when i send message with attachment at a time (TO: intranet address and internet address) , it is not blocking.
But In separate sending to internet and intranet , it is working fine...

what can i do for blocking to internet and allow to intranet at a time???????

My setting as follows:
To: * @domain.xx.com 10000000 #(10MB) (---for intranet)
To: default 0 (---- for internet)