Planning for anti-spam to reduce the massive number of spam messages that circulate nowadays through the Internet has become one of the most important tasks of message administrators. Unfortunately, spammers and malicious senders use a variety of techniques to send unwanted messages to your organization. No single tool or process can eliminate all spam.
By default the anti-spam agents are installed only on the Edge Transport server role. However, they can also be enabled on Hub Transport servers where needed.
Any change to the anti-spam agents is immediately activated. If, for example, you add an IP address to an IP Block List, it is immediately blocked without any service restart.