some mail not getting through

[http://dummy.us.eu.org/robert (Robert)]

Oddly, some sneakemail is not getting through.  In particular, my
"netflixdvdrental" (http://dummy.us.eu.org/robert) is not getting passed
through.  Because there is no way to view recent traffic, I cannot tell
whether sneakemail received it or not.  (I called Netflix and they assure
me that they had sent several emails to me.)

Are certain senders blocks, and would Netflix be among them?

Thanks.