I am running exchange 2007 SP2 on win 2003 R2 64bit.
I checked externally and I am NOT an open relay, but internally, I have a user via telnet and SMTP, they can send email as anyone in my organization to anyone, and I would like to know how to stop that? When using outlook 2007 or 2010, you can't send as someone else unless the user is given access, but why via telnet and the SMTP protocol, they can send as anyone they want.
Any help is appreciated.
I've checked to make sure I'm not an open relay with the following websites:
They both said I am NOT an open relay.