You know what it was...Im running IIS i had to adjust the DCOM settings for Hmailserver...Here is a link. In the instructions it says to set the internet guest account that doesn't work you have to set IIS_WPG and it works...If anyone is looking. Win2k3 IIS6.
DCOM permissions
Here the same problem on an W2003ServerR2-IIS6.0 machine.
I tried you advice. Standard the Internet Guest Account (WEBSERVER\IUSR_WEBSERVER), wass allready fully allowed. When I add IIS_WPG group and allow everything, it still not works. For test I added EVERYONE and allow everything. Then it works!
But now, I think EVERYONE will not be the sollution