We configured qmail for a mail server. We also used spamtitan. But we noted that spam mails relying thro' the secondary MX record. so, we removed the second one. but still we receive spam mails or junk from other servers. so we need to relay only thro' the specified server. To do this we had configured the file
/etc/tcprules.d/tcp.smtp
by allowing the ip of the particular server. Is there anything to restrict other than this.

We have added 0.0.0.0:allow,RELAYCLIENT="" in that file to mention that server's ip.
Is this correct. or we have to do anything more...