Hi runnning SBS and exchange 2003. about a week ago started having this problem. Mail sits in out queue. i clean everything out and restart the server and the connection is ok for awhile. then later it will queue again. also if sending from a pop account inside the network it gives the same error. no mail will go out via my isp. in exchange i am using my isp as smart host. cannot seem to get dns to work well enough. i have tried to telnet and get the same error. this has got me stumped.