DNS problem while tring to SMTP

[chenro]

I have implemented the SMTP in C# and in testing got the error: An internal DNS error caused a failure to find the remote server. (Event ID: 4000)
I wasn't able to send anything and all the messages just queued.
I saw an articale about this suggesting to open port 53 in the DNS but that didn't work either.
I am working with WIN2K and the IIS 5.0 I send emails from the localhost to remote account I have and I did relay to 127.0.0.1

Any ideas are very welcomed
chen

[Xoc]

It sounds as if .NET can't resolve the domain name into an IP address. Can you create a Command prompt and ping the domain name on the server?