Several people have reported problems receiving e-mails from Netflix, and a reader tipped me off that Netflix's e-mail server (mx.netflix.com) has been "blocklisted."
From the CBL spam-block database:
IP Address 18.104.22.168 [mx.netflix.com] was found in the CBL.
It was detected at 2006-04-27 13:00 GMT (+/- 30 minutes).
It has been relisted following a previous removal at 2006-04-20 15:54 GMT
If you do not want to receive e-mails or other contact from Netflix, you can set your preferences in the "My Account" section of the Netflix Web site.