We recently installed Exchange 2007 on Windows 2008 and everything has been running great. I do have one company that we are getting this error with and usually I wouldn't care as much, but it's our medical insurance company! I've attached a screen shot of the error and the details of the message in the queue. I also did an NSlookup form the server and it does return three mx records for the company. I'm lost and would like some guidance. There is no Edge server. Everything is on one server with our Sonicwall 3060's ports opened for SMTP 25. Any help would be great!