Unknown Sender

Hi!

My users are still receiving messages from the e-mail addresses that do not
exist in my global address list like no-reply@mydomain.com even after
selecting "Block Messages sent to recipients not listed in the Global Address
List" in Sender Reputation Filter Under Anti-spam settings in Exchange 2007.

Is there a way i can block these e-mails?

Thanks!

What you selected would block inbound mail to recipients not found in AD.

What you selected would block inbound mail to recipients not found in AD.
So, it does not matter if the *sender* is not in AD - the recipients of these
messages clearly *are*.

Look into Postini or other hosted antispam gateway service/appliance to
handle spam filtering for you. Works a lot better and your users will get a
quarantine notice.