GW8.0.1, GWIA running on SLES10SP2.

GWIA has stopped sending messages through, all outbound messages from
the GW system are being dropped into the send queue but never going
out. Incoming messages are processing just fine, web console for gwia
shows all links open. GWIA will restart fine, but still does not
process outbound mail--log file shows all outbound traffic being
queued. Suggestions?