White listed WebTV Address Held

I am a spamcop subscriber.  I have a regular correspondent that e-mails
me through Web TV.  He is not computer savvy; this is his only access to
 e-mail.  I find that his mails to me are usually sequestered in the
"Held Mail" area.  I have released this mail _countless_ times to be
whitelisted, and his address is in my whitelist.  Is there anything else
that I can do to allow his e-mails to by-pass the held mail area?

Sender's (modified) e-mail:

munged_ret (at) webtv (dot) net