Can't send if text entered in message body

[Rod]

I'm having a strange send error.

If I just put the recipient address and a subject, the
email will send. If I add ANY text to the message, when I
click "Send & Receive" it starts to send, I get the
progress bar, then it just sits there until it errors out.

I'm totally stumped by this one...any help out there?

Thanks,

Rod