Also, not contained in that document are a few troubleshooting steps that have been suggested:
If you have a signature, try removing one line at a time from it and attempting to send the message again. Some signatures look like "ads" to the filters, apparently.
If you are using a pop3 client (Outlook, Outlook Express, etc.) try sending your message from the verizon.net website. If this resolves the issue, then it is something that your client is adding to the message that is causing it to be blocked.
Those are excellent suggestions, thanks for posting.