6900: Email received, but won't send!

[NDJollyMon]

My new Verizon VX 6900 (pop3) email receives email, but won't send it. It just stacks it in a drafts folder and I get an error message:

"The outgoing mail server cannot send or receive messages at this time. Try again later."

My Yahoo.com mail account works fine on this phone, but the pop3 account (which is midco.net) won't send email. Text, MMS both work fine too.
As far as I can tell, all settings seem to be right. I deleted that account, and re-entered it...same thing. No send.

ANY CLUES to what may be wrong???