Ok, let's say for example that @yahoo.com is placed in the kill list to block out that domain due to spammers.  Now let's say that there is a single user in that domain that I want to allow through.  The only white list I find is for content filtering and it doesn't apply.  How do I allow that ONE or several address(es) to send mail, but still block out the rest of the domain?

I have this problem with several domains and addresses.

kill file is the first line of imail servers defence (SMTP Access control). there is no way to setup the white list for that processing step, only wild cards for Mail From address

If you need to provide such technique you need to use "Content Filtering"

Regards,
Dmitri Elgin,
http://imailzip.com