how can in stop unauthorised SMTP relay in exchange 2010..?

on HT server modify receive connectors and uncheck anonymous senders option.

Hi, By default, unauthenticated users can’t relay, even you checked anonymous users in receive connector. What’s your problem? Can you describe your environment and problem in detail? Thanks, Elvis

ok. i dont have any problems at the moment.. I want to make sure that am protected from spammers. I created a send connector,all other are in default settings.

Hi, Then you should not have a relay problem. For protect your server from spamming or other unwanted attack. I would suggest you using Forefront for Exchange: http://www.microsoft.com/forefront/en/us/secure-messaging-solution.aspx Thanks, Elvis