Am trying to install OpenDkim on ubuntu and zimbra 7 with Split DNS based on this guide Sign emails with OpenDkim + Postfix in Ubuntu 64x.

Now am stuck with one thing and i need some advice/idea.

On the part number 5. Adding the public key to your public DNS.

My question here is. Is it a must to add public key to our ISP or i can add on the bind9 configured on zimbra server and everything will be ok?

If so, then where should i add on the bind9(within zimbra server) files?

Thanks and Regards