Hello mshaty,
I found some information about troubleshooting false-positives in the iCloud junk mailbox:
Troubleshooting false-positives
Due to the complexity of accurately detecting and filtering out spam, on rare occasions a legitimate email from a friendly source may be blocked from reaching your Inbox. This is called a false-positive. If you feel that a legitimate email message was inadvertently filtered, you may want to ask your friend to send a follow up email to verify the issue exists before contacting support. If you notice that multiple email messages are being delayed, bounced, or not delivered, please contact iCloud Support directly.
Also make sure to check your Junk folder for email messages that were incorrectly marked as spam. To check your Junk folder from iCloud.com, choose the Mail application and click the Junk folder in the sidebar.
Note: Email messages in the Junk folder are automatically deleted after 30 days.
You can find the full article here:
iCloud: Identifying and filtering spam
http://support.apple.com/kb/HT4899
Thank you for using Apple Support Communities.
Best,
Sheila M.