Why is e-mail from Hotmail addresses blocked on my Yahoo e-mail account?

For some reason each time I am sent an email from a certain Hotmail account I never see it in my Yahoo inbox. It doesn't show up in the Junk folder either. And I have that Hotmail address in my address book. I get lots of emails from other domains OK. Help!
Why is e-mail from Hotmail addresses blocked on my Yahoo e-mail account?
Check your (Yahoo) blocked list, and remove the (Hotmail) address from the blocked list.


Mail page%26gt;%26gt;options (top right)%26gt;%26gt;mail options (if available)%26gt;%26gt;block addresses (under Spam).