Stop users from SMTP Mail

[Numbnutz]

Hello all, i am running exchange2k i want to stop a department or an "OU" from any SMTP access to the internet... but yet still need them to have access to the X400 for interal use only.... When i try to remove the SMTP it gives an error and tells that i can not remove the default SMTP.

[KINGofBLEH]

Block port 25 on your firewall. This will still allow internal SMTP traffic.