Ideally I would like to use an external mail server which has a great webmail and antispam, but it doesn't look like the whm configuration allows this. I actually have a mail server/antispam solution running that works great and I really would prefer to avoid the growing pains for the cpanel/whm email.
How can I at least set the configuration to use my regular mail server as a smarthost/smtp so that I can leverage my mature working antispam solution? What I would want would be to set the MX to the external server, only allow SMTP to CP from that host, and force all outgoing SMTP through that server. This should be the same setup as though the hosted domains were using Postini, so I assume (yeah, I know) that configuration is not totally unique.
Any hints, advice or RTFM pointers will be greatly appreciated.