Hello ,
i am looking for a solution since 1 month , we have exchange 2010 server with local antispam ( integrated with firewall )
anyone can do telnet ( exchange public ip ) port 25 and can send emails to the internal mailboxes user@mydomain.com
how can i disable the telnet so if any one try to send email from outside to local domain he will get error or ask for password .
i tried to uncheck ( anonymous users but that stopped the email flow and we could not receive any email from outside .
we had a serious issue because of this , some one from outside sent email using telnet to our CFO and he thought it was a valid email :(
please help please