Qmail errors

[Robert Ruzbacky]

Currently I am having a problem with qmail.  Our users are getting the following error when sending mail via SMTP:     "No transport provider was available for delivery to this recipient"   The client they are using is Microsoft Outlook.  I can send via Outlook express, and it works fine on my machine.  I check the qmail logs, but cannot find any bounce message.  The error bounces back to the user with systems administrator as the user.  With Microsoft Outlook, internet email is enabled as well as Microsoft Mail (the old win3.11 pop system) for internal mail.   Any ideas?  I am running a debian 1.3 server with qmail being v1.02.     Thanks   Rob..