OK, first of all, as pointed out in another thread, the "Incoming Gateway" section of the help for SmarterMail is really confusing. Its terminology is a bit vague and ambiguous. It is hard to tell if you're making that instance of SmarterMail an incoming gateway or if you're trying to configure that instance of SmarterMail to accept email from an incoming gateway. It needs work.
Now to my question. I'm using McAfee's Incoming Email protection service which is basically a SPAM filtering gateway. I changed my MX records to point to their servers. Problem is that the SPAMMERS are bypassing McAfee and using cached MX records or cached IP addresses and still going directly to my SmarterMail instance.
So, how in SmarterMail do I set to only accept incoming email from McAfee's filter servers (I have the IP addresses) and still be able to send email from my email clients? I'd like to avoid changing the IP address of my mail server if possible.
Thanks in advance!