I have a SBS 2003 running exhange on a 15 users office. But one of the account, a new one its not able to receiving external emails. If i send a email to this account with another office email example to: user1@office.com, user2@office.com, the person received the email, but if its single not. Thanks Jean

Hi Jean, Please check whether any NDR messages are received when sending message to the internal user from external account. In addition, I suggest that you enable SMTP log on the SBS server to check whether any error is encountered when receiving the message. Mike

Do you mean that if you send to the user from the Internet, you get no NDR? Or if you send internally. Do you have a 3rd party software or provider that is handling anti-spam and antivirus for you?