Host not found (Postfix)

Using SuSE 8.1 Postfix was working fine until yesterday, and now getting the following error when sending messages. /var/log/mail:Jan 19 11:19:12 neptune postfix/qmgr[829]: B14E51C24E: to=, relay=none, delay=0, status=deferred (Name service error for sloxmail: Host not found) sloxmail is in my hosts file, and a I can ping it by both name on IP, from the machine on which I'm getting this error. Any Suggestions? Thanks, Chuck