What is the difference between hosted and on-premises email security solutions?

The distinction made in the correct answer highlights the fundamental operational models for email security solutions. Hosted solutions, often referred to as cloud-based solutions, are managed by third-party providers who store, protect, and process email data off-site. This arrangement frees organizations from the burdens of managing infrastructure, software updates, and security features, as these responsibilities fall to the service provider. This can enhance flexibility, scalability, and accessibility for businesses that may not have extensive IT resources.

In contrast, on-premises solutions require organizations to maintain their own hardware and software within their own facilities. This means an internal team is responsible for the entire lifecycle of the email security system, including installation, maintenance, and updates, which can result in higher operational overhead and resource allocation.

The other options address factors such as cost, maintenance levels, and the existence of differentiation between hosted and on-premises solutions, which do not capture the essence of the primary operational difference between the two models. The most significant aspect is indeed the management and hosting environment of the solutions, which fundamentally impacts how businesses approach email security.