iPhone : I appear to have buggered up my mailbox

[Knipples]

Ok, so I decided to delete and re-add it because I knew I was getting emails (facebook notifications etc) and they weren't appearing in my inbox, so having deleted facebook and re-added that at the weekened, I did the same with my yahoo email.

However, it now seems to be broke. I have nothing displayed in the inbox, it tries to download it, and then stops, or sits there for ages saying its downloading it, but not actually doing it. I've deleted it once and added it again already, but am I doing something wrong.

I know its not the yahoo thats broke, cos I can go in via safari and access email that way, just its more of a faff to do it that way, and i'd like the email inbox fixed.

HELP!