Hello, maybe I have already posted this thread but I cannot see it in my threads so I submit it again. A customer wants that use almost all users be disabled from sending and receiving mail from internet. Only some people should be authorized to send outbound. In exchange 2003 I used delivery option in thesmtp connector and assigning only internal smtp address to users to obtain the goal. How this could be done with Exchange 2007? The customer has only 1 server with hub role, no one with edge role. Any suggestion welcome Nicola

Hi Nicola, Create a Distribution Group "NoInternetMail" & add all recipients who doesnt required to send & receive internet email. Prevent form Sending Mails: Create a transport rule on Hub Transport Server: Organization Configuration -> Hub Transport -> Transport Rules -> New Transport Rule -> Give Name TR No Internet MailConditions: select "From a member of a distribution list" & select created group "NoInternetMail" Select another condition "Sent to users inside or outside the organization" & Select Outside. Actions: select "send bounce message to sender with enhanced status code" & write your custom message like You are not authorized to send mails to internet Prevent from Receiving Mails: New User: You can select require that senders are authenticated while creating new users which will stop receiving mails from internet. User -> properties -> Mail Flow Settings -> Message Delivery Restrictions -> Properties -> set Sender Authentication. For Existing Users: You have already crated a group "NoInternetMail" & added users so set sender authentication for all members with this single command. Code SnippetGet-DistributionGroup "NoInternetMail" | Set-Mailbox -RequireSenderAuthenticationEnabled $true