I am running Exchange Server 2003 on Windows server 2003 and over the last few days noticed that mail just stopped flowing out. Mail is coming in fine but not going out. If i re-boot the server the mail is sent but then after about 10 minutes stops again. I have checked a few of the posts on experts exchange and some suggested it may be relaying. I have checked this but it isn't. Can someone please help me overcome this issue as i have now run out of ideas?