Deny SMTP TRAFFIC

[Mike Jimenez]

What it the proper way to block SMTP Traffic from certain hosts?
For example in the tcp.smtp file I have inserted the following.
200.35.83.68:deny
But I think will only block mail relaying rather than denying any email sent
to me from this host. Is this correct?
If someone can provide me with a solution on how to block incoming email
from certain hosts it would be greatly appreciated.
Thanks

Mike