Email server offline when online

Hi

Can anyone help me with an email send issue? My email will not send because the smtp server keeps saying it's OFFLINE, but everything I check says that it is ONLINE.

I was using email from this same server through the same connection earlier today, and suddenly... I am getting the "Cannot send message using smtp.mac server." When I look at the servers to choose from they are ALL listing as OFFLINE. But when I check anything and everything else, I am told everything is online.

I can access the internet, I can RECEIVE email, I just can't send!

HELP!!!

(I am on OS 10.5.8, by the way and am a shifting MobileMe-to-iCloud user... though that may change soon...)