I have been running hMail server on Windows 2003 for a couple years for several client domains. I have been getting complaints recently from clients they can no longer send email to Yahoo, for example, getting a response of 421 4.7.1 [TS03] , in other words my email server is sending a fair amount of spam. I checked my server at Multi-RBL Check from Anti-Abuse Project, and it is listed in about 4. When I check my logs on hMail, it does in fact show that my server is almost constantly having an SMTP session open, and a lot of specific non-authorized SMTP sessions are opened. I am not the absolute best at reading these logs, but I'm sure it has to do with something in my settings. Before I start trying to post a lot of settings, is there a specific set of settings that would be helpful in determining if they are correct to avoid spammers? Is there a setting elsewhere than hMail that I could look?