Message quota warning?

[J_Bone]

I received the following email on my phone (sprint pcs account):

"Your PCS Mail/Short Mail storage is 90%full. At 100%, messages will no longer be delivered. Delete messages from your inbox or other folders."

I have checked my folders and can't find anything. 1 or 2 messages here or there maybe. I have emptied the Deleted Items and all.

What am I missing? Is there somewhere to look for messages other than the obvious one under the pulldown menu in the top left of the message window?

Thanks guys.