OK, I got a list owner who says she has a subscriber who NEVER gets any
email from the list, but yet, if she sends directly to him at the same
address, he gets it.

The address looks like it might be a "Free" email account, but not hotmail.
Is there some log or something I can check to see if they are blocking our
listserv emails, but not individual emails to him?

Is this even remotely coherent?  I'm suffering from first week of semester
trauma :-)