Make sure you are on port 25, have authentication enabled, and that nothing such as your ISP, firewall, or anti-virus software is blocking your outbound port 25 access.
I speculated yesterday that it was a temporary glitch. This AM the email in question got sent automatically and cleared the outbox. Figures. Last time msn changed email servers they sent us an email telling the rollover date and how to set up our ports. Thanks anyhew.