No worries, doesn't surprise me with a Yahoo email address. The big box email providers (Yahoo, Gmail, AOL, Hotmail) have been getting increasingly tough on what they consider spam, even though we follow every rule in the book for opt-ins and easy unsubscribes. The problem with a health & fitness site is that inevitably we have something in the newsletters about that dreaded "diet" word and then we magically get lumped in with all the TV infomercial magic diet pill spammers.
You should be able to whitelist the sender address and it will deliver it to your Inbox from now on, though. Good call asking in here!